Development of CICC for KSTAR Superconducting Magnet System

The KSTAR (Korea Superconducting Tokamak Advanced Research) superconducting magnet system adopts a superconducting CICC(Cable-In-Conduit Conductor) type conductor. It consists of 16 TF (Toroidal Field) coils and 14 PF (Poroidal Field) coils and it also uses two different types of CICCs-Nb3Sn cable with Incoloy 908 conduit and NbTi cable with 316LN stainless-steel conduit. A special CICC jacketing system is developed for the KSTAR CICC fabrication: the tube-mill process, which consists of forming, welding, sizing and squaring procedure. The cabling process for TF and PF superconducting cable and the fabrication process of each CICCs (TF CICC and PF CICC) is described. The welding of conduit materials are also discussed. The fabrication results such as the geometrical specification, micro structure and the void fraction will be discussed