[1] Univ Padua, Ist Nazl Fis Nucl, ENEA, Consorzio RFX CNR,Acciaierie Venete SpA, Corso Stati Uniti 4, I-35127 Padua, Italy
[2] Univ Roma Tor Vergata, Dept Ind Engn, Via Politecn 1, Rome, Italy
[3] CIEMAT, Lab Nacl Fus, Av Complutense 40, Madrid 28040, Spain
[4] Max Planck Inst Plasma Phys, Greifswald, Germany