1. Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland
2. Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
3. Forschungszentrum, 52425 Juelich,
Germany
4. Laboratorio Nacional de Fusion, CIEMAT, Avenida Complutense, Madrid, Spain
5. Princeton Plasma Physics Laboratory,
Princeton, New Jersey 08540, USA