1. University of California-San Diego, La Jolla,
California 92093, USA
2. Swiss Plasma Center (SPC), Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
3. General Atomics, P.O. Box 85608, San Diego,
California 92186-9784, USA
4. Max-Planck-Institut für Plasmaphysik, D-17491
Greifswald, Germany
5. IPP.CR, Institute of Plasma Physics AS CR, Za
Slovankou 3, 182 21 Praha 8, Czech Republic