1. European Synchrotron Radiation Facility, Grenoble, France
2. European XFEL, Schenefeld, Germany
3. STFC, Daresbury Laboratory, Warrington, UK
4. Amplitude, Evry, France
5. Laboratoire pour l'Utilisation des Lasers Intenses (LULI), Ecole Polytechnique, CNRS, CEA, UPMC, Palaiseau, France