CRAFT TF Coil Winding Pack Insertion has been Completed Successfully

  On March 6, 2026, the CRAFT Toroidal Field (TF) magnet successfully completed winding pack (WP) insertion at the No. 8 workshop of the Comprehensive Research Facility for Fusion Technology in Hefei, laying a solid foundation for the smooth delivery and testing of the magnet.

  The WP insertion is a critical process and one of the key technical challenges in TF magnet manufacturing process. To achieve millimeter-level precision in assembling the WP with the coil case components named AU and BU, the project team conducted extensive preliminary research, scheme development, simulation calculations, process development, and process qualification on dummy WP assembly.  Ultimately, horizontal assembly scheme is adopted and serial of challenges, such as "virtual assembly technology based on precision measurement" and "heavy-load low-friction coating technology for G10 material surfaces" have been overcome. A set of complete and reliable operational procedures for WP insertion has been developed and qualified.

  The 240-ton TF WP, "riding" on 12 G10 sliding blocks coated with a low-friction layer, was successfully slid sequentially into the U-shaped inner cavities of the 120-ton AU component and the 197-ton BU component, achieving sub-millimeter precise positioning. This marked the successful fitting of the world's largest tokamak superconducting magnet coil with its perfectly matched "armor exoskeleton". 

WP has been successfully inserted into the coil case.