Winding Design for CFETR Central Solenoid Model Coil

In order to develop and verify the key manufacturing technologies of the large Nb3Sn superconducting magnet, the central solenoid model coil (CSMC) for China Fusion Engineering Test Reactor is being developed in the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), Hefei, China. The design value of the highest magnetic field for CSMC is 12 T, which is made of Nb3Sn and NbTi hybrid superconducting magnets. The key structural parameters of all windings have been determined by the electromagnetic design and optimization of the coil. All the windings of CSMC are a kind of pancake coil wound one in hand by cable-in-conduit conductor; each winding is composed of pancakes (concentric circular turns with turn transitions), pancake joggles, and upper and lower leads. The winding design has been finished including the winding direction analysis, the key bending segments geometry of turn transitions, pancake joggles, and leads transitions. Besides, the new winding production line has come into use and some key forming trials have been conducted.