1 GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
2 Institut für angewandte Physik, Technische Universität Darmstadt, Darmstadt, Germany
3 Helmholtz-Institut Jena, Jena, Germany
4 ELI-NP, Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH), Măgurele, Ilfov, Romania
5 Faculty of Physics, University of Bucharest, Măgurele, Ilfov, Romania
6 Center for Advanced Laser Technologies (CETAL), National Institute for Laser, Plasma and Radiation Physics (INFLPR), Măgurele, Ilfov, Romania