Mechanical Analysis of Helium Inlet and Outlet Structures in the Central Solenoid of the Next-Generation Fully Superconducting Tokamak

The central solenoid (CS) of a fully superconducting tokamak is a critical component for plasma initiation, shaping, and current drive, where reliable structural performance is essential for safe and stable operation. Helium inlet and outlet ports of the CS coil provide the necessary cooling pathways to maintain superconducting conditions at cryogenic temperatures. However, these structures are exposed to combined electromagnetic, thermal, and mechanical loads during operation, which can induce significant stresses, fatigue, and potential crack propagation. Ensuring their structural integrity is therefore crucial for both performance and safety. A multiphysics coupling analysis was conducted using finite element software to evaluate structural strength, fatigue life, and the maximum allowable initial defect area. The results show that the port structure can safely withstand operational loads while surpassing the device’s lifecycle requirement of 1 × 106 cycles.