1. DIFFER–Dutch Institute for Fundamental Energy Research, De Zaale 20, 5612 AJ Eindhoven, the Netherlands
2. CEA, IRFM, F-13108 Saint Paul Lez Durance, France
3. Aix-Marseille University, CNRS, PIIM, UMR 7345, 13013 Marseille, France
4. CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
5. Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland