Accelerator Tunnel of European XFEL (IMAGE) Deutsches Elektronen-Synchrotron DESY Caption This is a view into the 2.1-kilometre long accelerator tunnel of European XFEL with the yellow superconducting accelerator modules hanging from the ceiling Credit photo: DESY/D. Noelle Usage Restrictions Photo with proper credit line may be used for journalistic purposes free of charge. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.