Nov 27 2007
DESY celebrates the topping-out ceremony for the experimental hall of PETRA III – the new source of especially brilliant X-ray light in Hamburg. On occasion of the structural completion of the building, German Research Minister Dr. Annette Schavan and Hamburg’s First Mayor Ole von Beust visited the Helmholtz research centre DESY. Its new light source PETRA III is due to be completed in 2009.
“PETRA III is a milestone on the way to a world leading centre for interdisciplinary research with photons in Northern Germany,” said Research Minister Schavan. “In two years already, scientists from all over the world will be able to carry out research here in Hamburg, paving the way for innovations that will make our lives easier.”
“With its very brilliant, short-wavelength X-rays, PETRA III will be one of the world’s leading light sources,” said Prof. Albrecht Wagner, the Chairman of the DESY Directorate. “PETRA III will offer excellent experimental opportunities for a great variety of applications – from medicine to materials research. At present, a unique combination of light sources is being realized here at DESY which will attract numerous scientists from Germany and abroad to Hamburg.”
Hamburg’s Science Senator Jörg Dräger added: “PETRA III is another important pillar of top-level research in Hamburg. Together with the free-electron laser FLASH and the European X-ray laser XFEL, a worldwide unique centre of structural research is being created at DESY.”
One decisive advantage PETRA III has to offer is its hair-thin X-ray beam. Researchers can use it to study even minuscule material samples and precisely determine the arrangement of their atoms. Molecular biologists can explore the atomic structure of tiny protein crystals, in order to find the basis for developing new drugs. Materials researchers need the highly energetic radiation to test welding seams or to check production parts for signs of fatigue. Above all, structural and dynamical analyses of nanoparticles or measurements with a spatial resolution in the 10-nanometre range will benefit from the extremely well focusable X-rays.
For the new light source, DESY is completely rebuilding the existing 2.3-kilometre-long ring accelerator PETRA. The new experimental hall will be almost 300 metres in length, and its shape will conform to the curved contour of the accelerator ring. An area of about 10 000 square metres will contain 14 experimental stations that can accommodate up to 30 experiments.
“The PETRA III project is progressing very dynamically,” said Project Leader Prof. Edgar Weckert. “In parallel to the construction of the experimental hall, we’ve started to fit the 2.3-kilometre-long PETRA storage ring with completely renewed components. In addition, we established the scientific programmes of all the experiments, and we are now preparing them vigorously.”
Exploring the nanoworld with PETRA III is also a challenge with respect to construction technique. The hall floor is cast as a single one-metre-thick concrete slab that will support both the accelerator and the experiments. The slab is isolated from the vibrations of the rest of the building. To also minimize the influence that the building could exert through the ground on the hall floor, the latter is supported on sleeved piles extending 20 metres below the surface. Anchored in concrete at that depth, these supports are surrounded by a low-friction casing preventing direct contact with the upper layers of the soil. This allows any force acting on the piles to be transferred deeper into the ground and thus reduces distortions at the surface.
The worldwide finest X-ray beam offered by PETRA III is generated by means of special undulators, long magnet arrangements that produce a beam of very high brilliance. In order to guarantee that the optimal radiation can be delivered at the experimental stations for the most varied applications, the future users from universities and research institutions have been strongly involved already in the planning of the PETRA III project.
The construction of the new X-ray source will cost a total of 225 million Euros. It is financed mostly from funds of the Federal Ministry of Education and Research, the Free and Hanseatic City of Hamburg and the Helmholtz Association. In addition, around 25 million Euros for experimental setups are contributed by partner institutions like EMBL (European Molecular Biology Laboratory), the research centre GKSS (Geesthacht), the Max Planck Society and the Universities of Hamburg and Lübeck.