European XFEL

European XFEL. The European XFEL is a research facility generating extremely intense X-ray flashes for scientific experiments. It is one of the world's largest and most advanced X-ray free-electron lasers, enabling researchers to map atomic details of viruses, film chemical reactions, and study processes in the interior of planets. The facility is located primarily in the German federal states of Schleswig-Holstein and Hamburg, with its main experimental campus in the town of Schenefeld.

Overview

The European XFEL is a major international research infrastructure, conceived and built by a consortium of 12 countries. It operates as a non-profit company, with its largest shareholder being the German research center DESY in Hamburg. The facility's superconducting linear accelerator, the heart of the machine, is 1.7 kilometers long and is housed in tunnels extending from the DESY site in Hamburg to Schenefeld. This strategic location leverages existing expertise and infrastructure from DESY's FLASH facility. The project represents a significant collaboration in European science, with partner countries including Denmark, France, Italy, Poland, Russia, Spain, Sweden, and Switzerland.

Scientific capabilities

The facility produces ultrashort X-ray pulses with properties far exceeding those of conventional synchrotron light sources. These pulses are characterized by extreme peak brightness, a wavelength as short as 0.05 nanometers, and a duration of less than 100 femtoseconds. This allows for a technique known as serial femtosecond crystallography, where the diffraction pattern of a single molecule or nanoparticle can be captured before it is destroyed by the intense beam. Scientists can conduct experiments in fields such as structural biology, materials science, chemistry, and planetary science. Key instruments include the SPB/SFX instrument for biological studies and the HED instrument for high-energy density physics, enabling research akin to that conducted at the Linac Coherent Light Source and the Saclay-based SOLEIL synchrotron.

Technical design

The European XFEL is based on a superconducting linear accelerator technology, which allows for a high repetition rate of up to 27,000 pulses per second. Electrons are first generated and accelerated in a 1.7 km long linear accelerator built in a tunnel beneath the Hamburg metropolitan area. These high-energy electrons are then directed through long arrays of alternating magnets called undulators, located in the experimental hall in Schenefeld. The undulators force the electrons onto a slalom path, causing them to emit the powerful, laser-like X-ray radiation. Critical technological contributions came from institutions like DESY, the Paul Scherrer Institute, and international teams, building upon pioneering work at SLAC National Accelerator Laboratory and SPring-8.

Research and discoveries

Since commencing user operation, the European XFEL has facilitated groundbreaking studies across multiple disciplines. In structural biology, it has been used to determine the atomic structure of complex proteins and enzymes without the need for large crystals, advancing research into diseases and drug design. In chemistry, teams have filmed the breaking and formation of chemical bonds during reactions. Research in condensed matter physics has revealed hidden magnetic states and charge density waves. Furthermore, experiments simulating the extreme conditions inside giant planets like Jupiter or Saturn have been conducted, providing insights into planetary formation. These discoveries are regularly published in leading journals such as *Nature* and *Science*.

Operation and governance

The facility is operated by the European XFEL GmbH, a non-profit company with shareholders from the partner countries. The council of shareholders, which includes representatives from organizations like the Helmholtz Association and the CNRS, provides strategic oversight. Scientific access is granted through a competitive peer-review proposal system managed by an independent panel, similar to processes at other major facilities like the European Synchrotron Radiation Facility and the Advanced Photon Source. Day-to-day management is led by a managing director, currently Robert Feidenhans'l, with scientific direction provided by a team of leading researchers. The annual operating budget is funded by contributions from the member states, with Germany providing the largest share.

Category:Research institutes in Germany Category:X-ray free-electron lasers Category:Buildings and structures in Schleswig-Holstein Category:2017 establishments in Germany