1. Department of Applied Physics, Ghent University, Rozier 44, B-9000, Ghent, Belgium
2. EURATOM/UKAEA Fusion Association, Culham Science Center, Abingdon OX14 3DB, United Kingdom
3. Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stat: Unit: 4 I-35127 Padova, Italy