Commissioning of the European XFEL

The European X-ray Free-Electron Laser (EUROPEAN XFEL) in Hamburg, Northern Germany, was built to produce X-rays in the range from 0.25 up to 25 keV out of three undulators that can be operated simultaneously with up to 27,000 pulses per second. The EUROPEAN XFEL is driven by a 17.5 GeV superconducting linac. This linac is the worldwide largest installation based on superconducting radio-frequency acceleration, using the so-called TESLA technology which was developed for the superconducting version of an international electron positron linear collider. The construction of the European XFEL has been finished at the end of 2016 and commissioning has been started. Meanwhile the entire facility, driving 3 Free-Electron-Lasers in the hard and soft X-ray regime, is in operation. This contribution will report on commissioning and the transition to user operation.