N. P. Dover⁹, T. Dzelzainis⁵, O. Ettlinger⁹, M. Gauthier¹, L. Giuffrida¹⁰, R. J. Gray^11,12, J. S. Green⁵, G. S. Hicks⁹, C. Hyland⁶, V. Istokskaia^10,13, M. King^11,12, B. Loughran⁶, D. Margarone^10,6, O. McCusker⁶, P. McKenna^11,12, Z. Najmudin⁹, C. Parisuaña^1,14, P. Parsons⁶, C. Spindloe⁵, M. J. V. Streeter⁶, D. R. Symes⁵, A. G. R. Thomas⁸, N. Xu⁹, S. H. Glenzer^1,†, and C. A. J. Palmer^6,‡

• ¹SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
• ²Department of Applied Physics, Stanford University, Stanford, California 94305, USA
• ³Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany
• ⁴Lawrence Livermore National Laboratory, Livermore, California 94550, USA
• ⁵Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX, United Kingdom
• ⁶School of Mathematics and Physics, Queen's University Belfast, Belfast, United Kingdom
• ⁷Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
• ⁸Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109-2099, USA
• ⁹The John Adams Institute for Accelerator Science, Imperial College London, London SW7 2AZ, United Kingdom
• ¹⁰ELI Beamlines Facility, The Extreme Light Infrastructure ERIC, Za Radnicí 835, 25341 Dolní Břežany, Czech Republic
• ¹¹Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG, United Kingdom
• ¹²The Cockcroft Institute, Sci-Tech Daresbury, Warrington WA4 4AD, United Kingdom
• ¹³Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague, Czech Republic
• ¹⁴Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA

• ^*Contact author: gdglenn@slac.stanford.edu
• ^†Contact author: glenzer@slac.stanford.edu
• ^‡Contact author: c.palmer@qub.ac.uk