1. Linac Coherent Light Source, SLAC National Accelerator Laboratory 1 , 2575 Sand Hill Road, Menlo Park, California 94025, USA
2. SLAC National Accelerator Laboratory 2 , 2575 Sand Hill Road, Menlo Park, California 94025, USA
3. RIKEN SPring-8 Center 3 , 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
4. European XFEL GmbH 4 , Holzkoppel 4, 22869 Schenefeld, Germany
5. Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY 5 , Notkestr. 85, 22607 Hamburg, Germany
6. University of Michigan 6 , 500 S State St, Ann Arbor, Michigan 48109, USA
7. University Bordeaux, CNRS, CEA, CELIA, UMR 5107 7 , F-33500 Talence, France
8. Department of Physics, University of California 8 , Berkeley, California 94720, USA
9. Helmholtz-Zentrum Dresden-Rossendorf 9 , 01328 Dresden, Germany
10. Japan Synchrotron Radiation Research Institute 10 , 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
11. Deutsches Elektronen-Synchrotron DESY 15 , Notkestr. 85, 22607 Hamburg, Germany