1. Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi,”, Università di Bologna, Bologna, Italy
2. ENEA, Fusion Department, Frascati, Italy
3. Institute for Technical Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
4. Department of Energy “Galileo Ferraris,”, Politecnico di Torino, Torino, Italy