[1] Assoc EURATOM ENEA Fus, Consorzio RFX, Padua, Italy
[2] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA
[3] Ecole Polytech Fed Lausanne, Assoc Euratom Confederat Suisse, Ctr Rech Phys Plasmas, CH-1015 Lausanne, Switzerland
[4] Max Planck Inst Plasma Phys, Greifswald, Germany
[5] ORNL Fus Energy Div, Oak Ridge, TN USA
[6] Princeton Plasma Phys Lab, Princeton, NJ 08543 USA
[7] EURATOM, Max Planck Inst Plasmaphys, D-85748 Garching, Germany