Installation and commissioning of the European XFEL beam transport in the first two beamlines from a metrology point of view

The European XFEL is a large x-ray free-electron laser facility under construction in the Hamburg area of Germany. It is designed to provide a transversally fully coherent x-ray radiation with outstanding characteristics: high repetition rate (up to 2700 pulses with a 0.6 ms long pulse train at 10 Hz, for a total of 27 000 pulses/s), short wavelength (down to 0.05 nm), short pulse (in the femtosecond scale), and high average brilliance [1.6 × 10²⁵ photons/s/(mm²/mrad²)/0.1% bandwidth]. Five main beamlines are foreseen, with three fully financed and installed, called SASEs (from “self-amplified spontaneous-emission”): SASE1 (hard x-rays, 3–25 KeV), SASE2 (hard x-rays, 3 to possibly 60 KeV with the use of a third harmonic), and SASE3 (soft x-rays, 0.3–3 KeV). For each beamline, two separate scientific instruments will be served using the beam alternately in 24-h, 7-day shifts. The installation and commissioning of the European XFEL beamlines are proceeding rapidly. So far, the hard x-ray SASE1 beamline and the soft x-ray SASE3 beamline, both injected with the same electron beam, have been installed and fully commissioned. SASE1 already delivers beam to the corresponding stations and has been open for external users since September 2017. The SASE3 beamline was successfully commissioned in February 2018, and the simultaneous operation of SASE3 and SASE1 was also demonstrated. In the meantime, the SASE2 beamline is being equipped and will be commissioned starting October 2018. We present the last results in the SASE1 and SASE3 beam transport, taking consideration in particular of the metrology carried out before the installation, the installation itself, and the final commissioning. The different stages were crucial to have good quality optical beam and fast commissioning to proceed with the delivery to experiments and users.