First Results of the Magnetic Measurements of the Superconducting Magnets for the European XFEL

The European X-ray Free Electron Laser facility (XFEL) is currently under construction at DESY in the Hamburg area in Germany. A linear accelerator consisting of 102 accelerator modules is used to accelerate the electron beam. Each module contains eight superconducting RF cavities and one magnet package, all operating in a 2 K super-fluid helium bath. Each magnet package consists of three nested magnets. Two cos θ-type correction dipole magnets horizontal and vertical deflecting are glued onto the surface of the beam pipe being the inner wall of the cryostat vessel. They are inside of a superferric quadrupole magnet. Each magnet package together with a conduction cooled current lead assembly, based on a CERN design, will be tested at room temperature and at 2 K in a special cryostat XMTS at DESY. It allows access for the field measurement equipment into the magnet bore at room temperature by using an anti-cryostat. The cold magnet project is realized by three groups as in kind contributions to the XFEL project. CIEMAT designs and provides the magnets and DESY the current leads. Magnet testing at DESY is performed together with IFJ PAN. A description of the XMTS facility, the magnetic field measurement systems used (harmonic coils and stretched wire setups) are given. Finally a short discussion of the results obtained for the first third of the magnets is presented. All magnets tested so far perform very well up to the design current. The quality and strength of the magnetic field are as designed.