1. Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218, Moscow, Russia
2. Moscow Engineering and Physics Institute, Dept. of Extreme States of Condensed Media, 115409, Moscow, Russia
3. Institute of Radiation Physics, Helmholtz-Zentrum, Dresden-Rossendorf P.O. Box 510119, 01314, Dresden, Germany
4. Martin-Luther-University Halle-Wittenberg, Dept. of Physics, 06099, Halle, Germany