The photon beamline vacuum system of the European XFEL

• Published in: Journal of synchrotron radiation Vol. 28; no. 4; pp. 1229 - 1236
• Main Authors: Dommach, Martin, Di Felice, Massimiliano, Dickert, Bianca, Finze, Denis, Eidam, Janni, Kohlstrunk, Nicole, Neumann, Maik, Meyn, Frederik, Petrich, Michaela, Rio, Benoit, Sinn, Harald, Villanueva, Raúl
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01.07.2021; John Wiley & Sons, Inc
• Subjects: beam transport system; Beamlines; Geometrical optics; photon beamlines; Photon beams; Photons; vacuum; Vacuum systems; XFEL
• ISSN: 1600-5775; 0909-0495; 1600-5775
• DOI: 10.1107/S1600577521005154

The photon beamline vacuum system of the European X‐ray Free‐Electron Laser Facility (European XFEL) is described. The ultra‐large, in total more than 3 km‐long, fan‐like vacuum system, consisting of three photon beamlines is an essential part of the photon beam transport. It is located between the accelerator vacuum system and the scientific instruments. The main focus of the design was on the efficiency, reliability and robustness of the entire system to ensure the retention of beam properties and the operation of the X‐ray optics and X‐ray photon diagnostics components. Installation started in late 2014, the first of the three beamline vacuum systems was commissioned in spring 2017, and the last one was operational in mid‐2018. The present state and experience from the first years of operation are outlined. A description of the photon beamline vacuum system of the European XFEL is given, together with experiences gained during the first years of operation.