Study on Performance Improvement of TF Superconducting Magnet With High-Strength Nitronic 50 for Next Generation Fusion Device

The toroidal field (TF) magnet constitutes a pivotal component within a Tokamak fusion reactor, serving the essential function of generating high magnetic fields requisite for plasma confinement. However, the high magnetic fields introduce additional challenges to the structural safety of TF magnets. This paper aims to investigate the performance of TF magnet when utilizing N50 material. Employing a fusion device's TF magnet as a case study, a comparative analysis involving N50, JJ1, and 316LN materials was conducted. Initiating with an overview of research and development endeavors pertaining to N50, this investigation proceeds to construct and delineate a 2D finite element model of the inner leg cross-section of the TF magnet. Subsequent to this, electromagnetic analysis and thermal, electromagnetic, mechanical coupling analyses are executed. The findings indicate a notable enhancement in performance with the adoption of N50 material, evidenced by an increase in the central magnetic field from 6.2 T (using 316lN) to 7.3 T with N50. This translates to a commendable 1% augmentation in fusion energy. Finally, the research and development efforts on N50 are outlined. The yield stress of N50 base metal used in jacket and TF coil case is 1515 MPa and 1250 MPa. Consequently, the utilization of N50 material exhibits the potential to substantially ameliorate the overall performance of the tokamak machine.