Mechanical engineering challenges at European XFEL

Research facilities like European XFEL, located in Hamburg, Germany, are innovative hard X-ray photon sources that allow the exploration of previously inaccessible research areas. With the help of the 3.4 kilometre-long, underground machine, the scientists 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. To deliver the X-rays to the experimental stations, the photon beam has to be manipulated by optical elements that have to preserve the unique properties of the photon beam. The optical elements are mounted in Ultra High Vacuum (<10-8 mbar) environment, have to be aligned and adjusted with high resolution (below 100 nm) and repeatability. The photon distribution system is 1 km long and the optical element have to drive the photons to the experimental targets with sub-micrometre accuracy. Therefore, mechanical stability and minimization of vibrations are paramount. A small part of the photon beam is absorbed by the optical elements and to avoid thermal drifts and minimize deformation of the perfect optical surface, cooling solutions based on eutectics are implemented. This contribution gives an overview of challenges and solutions for UHV compatible, high precision mechanics that support and remote control cooled optical elements for X-ray transport.