1. Institute of Physics of the ASCR, ELI-Beamlines Project, Na Slovance 2, 182 21 Prague,
Czech Republic
2. ICFO—Institut de Ciencies Fotoniques, Barcelona Institute of Science and Technology, Av.
Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona),
Spain
3. National Research Nuclear University MEPhI, Kashirskoe Ave. 31, 115409 Moscow,
Russia
4. Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str. 38, 119991 Moscow,
Russia