1. Lawrence Livermore National Laboratory, Livermore, California 94550, USA
2. Dr. Remeis-Sternwarte & ECAP, Universität Erlangen-Nürnberg, 96049 Bamberg, Germany
3. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
4. Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom