1. Center for Free-Electron Laser Science (CFEL) Deutsches Elektronen-Synchrotron DESY Notkestrasse 85 22607 Hamburg Germany
2. The Hamburg Center for Ultrafast Imaging University of Hamburg Luruper Chaussee 149 22761 Hamburg Germany
3. Instituto Carlos I de Física Teórica y Computacional and Departamento de Física Atómica, Molecular y Nuclear Universidad de Granada 18071 Granada Spain
4. Department of Physics University of Hamburg Luruper Chaussee 149 22761 Hamburg Germany