The European XFEL is a research facility of superlatives: It generates ultrashort X-ray flashes—27 000 times per second and with a brilliance that is a billion times higher than that of the best conventional X-ray radiation sources.

Starting in September 2017, the world's largest X-ray laser will open up completely new research opportunities for scientists and industrial users.


Smaller, faster, more intense: The European XFEL will open up areas of research that were previously inaccessible. Using the X-ray flashes of the European XFEL, scientists will be able to map the atomic details of viruses, decipher the molecular composition of cells, take three-dimensional images of the nanoworld, film chemical reactions, and study processes such as those occurring deep inside planets.

How the X-ray laser works

To generate the X-ray flashes, bunches of electrons are first accelerated to high energies and then directed through special arrangements of magnets (undulators). In the process, the particles emit radiation that is increasingly amplified until an extremely short and intense X-ray flash is finally created. More about how it works.

The European XFEL generates X-ray radiation with properties similar to those of laser light. There are several light sources with different characteristics. More about the light sources.


The European XFEL is located mainly in underground tunnels which can be accessed on three different sites. The 3.4 kilometre-long facility will run from the DESY campus in Hamburg to the town of Schenefeld in Schleswig-Holstein. At the research campus in Schenefeld, teams of scientists from all over the world will carry out experiments using the X-ray flashes.

European XFEL GmbH

To construct and operate the European XFEL, international partners agreed on the foundation of an independent research organization – the European XFEL GmbH, a non-profit limited liability company under German law. When user operation starts in September 2017, the company will employ more than 300 people. At present, 11 countries are participating in the project: Denmark, France, Germany, Hungary, Italy, Poland, Russia, Slovakia, Spain, Sweden, and Switzerland. The United Kingdom is in the process of joining the European XFEL as the twelfth member state.


The European XFEL has been realized as a joint effort of many partners. The European XFEL GmbH cooperates closely with the research centre DESY and other organizations worldwide. Construction started in early 2009; the start of user operation is planned for September 2017.

The construction costs of the facility, which include the commissioning, amount to 1.22 billion euro (price levels of 2005). As the host country, Germany (the federal government, the city-state of Hamburg, and the state of Schleswig-Holstein) covers 58% of these costs. Russia bears 27% and the other international partners between 1% and 3%.

To a great extent, the European XFEL facility was realized by means of in-kind contributions by shareholders and partners.