Development of ITER TF Coil Assembly Technique, Integration of Winding Pack into Coil Case

Abstract

Synopsis : The ITER Toroidal Field (TF) coil is a D-shaped superconducting magnet. A set of 18 TF coils forms a donut shape when assembled around the ITER vacuum vessel. The magnetic property of a coil is characterized by a current center line (CCL). To serve their function as plasma containment magnets, severe requirement of φ2.6 mm cylindrical tolerance is defined for the critical portion of the TF coils. In previous study, the manufacturing tooling and procedure have been developed and applied for manufacturing of Winding Packs (WP) and TF Coil Case (TFCC) subassemblies. In integration of a WP into a TFCC, predetermined CCL of the WP shall be controlled and transferred to reference points of the TFCC. For precise control of the CCL positions, deformations of the WP and the TFCC must be controlled. Also, the precise tracking of the CCL position required some techniques to evaluate the CCL positions even after the WP is completely covered by the TFCC. Techniques have been developed through welding trials and structural simulation analysis. Those techniques are applied to TF coil production and two TF coils have been completed successfully.