Overview of the Design Status of the Superconducting Magnet System of the CFETR

• Published in: IEEE transactions on applied superconductivity 2018-04, Vol.28 (3), p.1-5
• Main Authors: Zheng, Jinxing, Song, Yuntao, Liu, Xufeng, Lu, Kun, Qin, Jinggang
• Format: Article
• Language: English
• Subjects: CFETR; Coils; Conductors; magnet; phase II; Plasmas; Solenoids; superconducting; Superconducting magnets; Toroidal magnetic fields
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2018.2797965

The concept design of the China Fusion Engineering Test Reactor (CFETR) was started in 2012 in two stages. For CFETR-Phase I, the major radius is 5.7 m, the minor radius is 1.6 m, and the magnetic field at the plasma region, B T , is 4-5 T. There were 16 toroidal field coils and six central solenoid coils designed by a Nb 3 Sn cable-in-conduit conductor (CICC) with the maximum operation current of 64 and 50 kA, respectively. Three types of plasma equilibrium configuration (ITER-like single null, super-X, and snowflake) were designed. The maximum flux provided by the central solenoid is set at 180 V·s. However, to get much higher operation parameters such as steady-state operation, particle and heat exhaust, disruption mitigation and avoidance, ELM control, and material damage by high heat flux and neutron, the superconducting magnet system of CFETR-phase II has been updated based on the larger machine with R = 6.7 m-7.0 m, a = 2.0 m, and B T = 6.5-7 T. Such a new design makes over 1-GW fusion power and better plasma performance possible. Hybrid TF coils are designed by a high-performance Nb 3 Sn conductor, since the maximum magnetic field can reach to 14-15 T. Besides, in order to save the space for the blanket system and get higher flux, a high-temperature superconducting Bi-2212 magnet with better current-carrying performance under high field is supposed to be employed for the CS coils of CFETR-phase II. The Bi-2212 CICC sample has been tested at 4.2 K with a critical current of 26.6 kA under its self-field.