Today, European XFEL held the topping out ceremony for its headquarters building in Schenefeld in the German federal state of Schleswig-Holstein. The event marked a milestone in the construction of the X-ray free-electron laser, which is one of Europe’s largest new international research facilities. Over 350 guests, including representatives from the federal government, the states of Schleswig-Holstein and Hamburg, the consular corps, local politics and administration, the European XFEL Council, and European XFEL employees and their colleagues from DESY, recognized the accomplishments of the construction workers over the past year.

The headquarters building is constructed atop an underground experiment hall. The complex is 3.4 km away from the starting point of the facility in western Hamburg and is linked by a system of tunnels. When complete, the European XFEL will be a user facility open to scientists around the world. They will be able to study the nanocosmos using flashes of X-ray light a billion times brighter than those of traditional light sources. The scientists will work in the experiment hall, which was completed in 2013, and in the headquarters’ ground floor, which is equipped with laboratories for biology, electron microscopy, and sample preparation. The three-storey building will also house the facility’s offices.

“Today we celebrate another important milestone”, European XFEL Managing Director Massimo Altarelli told the attendees in a speech at the ceremony. “I would like to thank everybody who took part in the construction of this building. This is an important contribution to build a new research centre of worldwide significance here in Schenefeld until 2017.”

The ceremony kicked off with a traditional toast given by the foreman of the construction site in honour of the construction workers. After a short programme, which included remarks from dignitaries and a short film about the construction progress, the attendees toured the underground experiment hall.

 “The headquarters of the European XFEL is another important step on the way to the most powerful X-ray laser in the world”, said Hamburg Senator for Science and Education Dorothee Stapelfeldt. “This could only be realized in Hamburg and Schleswig-Holstein because the grand idea of the European XFEL has strong partners all over Europe.”

“Today marks a new phase in the realization of the European XFEL. With this facility, we will strengthen science in Schleswig-Holstein and in Europe”, Schleswig-Holstein State Secretary for Science and Research Rolf Fischer said in his talk. “The European XFEL has brought many nations together to see this facility through in a way that none of them alone could.”

"Looking at the headquarters building, one can already well imagine that soon many scientists will use this facility for world-class research", said Dr. Beatrix Vierkorn-Rudolph, head of the Subsection for Large Facilities, Energy and Basic Research. "But while we today can celebrate great progress, some work remains to be done, particularly with the technical installations."

“European XFEL will make Schenefeld an important location for the international scientific community worldwide”, European XFEL Council Chair Martin Meedom Nielsen said in his remarks to the attendees. “Scientists will take their experiences back home with them, and make the hospitality of Schenefeld known throughout the world.”

“The topping out of the main building is an important milestone in the realization of one of the most important future projects in Europe and in the world”, said Helmut Dosch, director of DESY. “DESY is currently working intensively on the installation of the superconducting accelerator, so that the next milestone, the commissioning of that machine, can be accomplished within schedule.” The Hamburg-based research centre is the European XFEL’s largest shareholder and will operate its 2 km-long linear electron accelerator.

The facility has been under construction since 2009, and work on the headquarters building, the final major aboveground structure to be erected, started in May of last year. Construction and commissioning of the facility is supported by 11 countries.

Work will continue throughout 2015 on the completion of the building. European XFEL employees will move into the headquarters building next year as they prepare for the beginning of user operation in 2017.