In order to verify key techniques and manufacturing aspects of the central solenoid (CS) coil of the China fusion engineering test reactor (CFETR), the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) plan to develop a CS model coil. The conceptual design of the CS model coil of CFETR has been carried out by ASIPP. The CS model coil shall produce a 12-T peak field in the bore of the magnet. The maximum magnetic field change rate is 1.5 T/s. The designed operating current is 47.65 kA. The CFETR CS model coil structure design mainly includes coil winding design, buffer zone design, preload structure design, coil joints and joint supports design, and liquid helium cooling channels design. This paper presents the conceptual design of CFETR CS model coil structure based on electromagnetic design and optimization.

A central solenoid model coil (CSMC) is being developed to veri-fy the large-scale Nb3Sn superconducting coil manufacture technologies for China Fusion Engineering Test Reactor (CFETR) in ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences). The CSMC composed of Nb3Sn and NbTi hybrid superconducting magnet can reach to the maxi-mum magnetic field 12 T. All of the Nb3Sn and NbTi coils are composed of pancakes windings, pancake joggles and upper & lower leads. For the multi-pancakes, the radial dimensions are from 1500 mm to 3544.8 mm and the maximum axial height is 1545.4 mm. High manufacture accuracy must be acquired for coil continuous winding, i.e. the innermost and outermost circu-lar turn surface profile tolerance is 2 mm and the conductor feeding tolerance is 0.5%L. The winding R&D activities, includ-ing the continuous winding for the pancakes and the on-line forming for the joggles, have been conducted to optimize and fi-nalize the coil design as well as to carry out the coil winding technology verification and improvement. Now, the continuous winding for double pancakes (DPs) of the Nb3Sn inner coil have been finished. The details have been described in this paper.

A large scale research and development project for China Fusion Engineering Test Reactor (CFETR) named the comprehensive research facility for fusion technology (CRAFT) started in 2019 and is scheduled for completion in 2025. A super-conducting conductor experiment testing platform (Super-X for short) is a sub-task of CRAFT to evaluate the future supercon-ducting part performance. The maximum testing magnetic field at bore center is 15 T, the dimensions of testing space are 100 × 160 × 550 mm, the field homogeneity of testing space is superior to 95%, and the maximum testing current is 100 kA. The direct current (DC) magnet is the key sub-system for the facility provid-ing the background magnetic field. The engineering design for DC magnet has been accomplished in the middle of this year, and its technical parameters meet the required. The main work focus-es on the structural design of the split coils, the axial preload and the hanging assembly. This paper presents the progress on the engineering design of the DC magnet.

The engineering design of the China Fusion Engineering Test Reactor (CFETR) has been completed in 2020. A largescale R&D project for CFETR named the comprehensive research facility for fusion technology (CRAFT) was initiated in Sep. 2019. As a sub-task of the CRAFT, a superconducting experiment testing platform (Super-X for short) is planned to be constructed for evaluating the future superconducting parts performance. Its main technical parameter includes: the background field of 15 T, the dimensions of testing space of 100 × 160 × 550 mm, the field homogeneity of testing space ≥ 95%, and the maximum testing current of 100 kA. For now, the preliminary design for Super-X has been accomplished. The DC magnet provides the background magnetic field for Super-X. It is a kind of split coil that includes two symmetrical coils assemblies. The innermost diameter is about 644 mm, the outermost diameter is 2874 mm. Each coil assembly is composed of three concentric Nb ₃ Sn coils. The peak field is 15.7 T and the field homogeneity reach to 98.2%. The high field coil (HFC) and medium field coil (MFC) is typically dominated by high-J _c Nb ₃ Sn cable-in-conduit conductor (CICC), and the low field coil (LFC) by ITER grade Nb ₃ Sn CICC. This paper presents the preliminary design of the background DC magnet system (BM).

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.