Stability and Quench Analysis of Toroidal Field Coils for ITER

Stability and quench analyses of the ITER TF coils are performed with a combination of three computer codes to obtain an accurate prediction. A one-dimensional code ldquoGandalfrdquo with an adaptive mesh is used mainly for these analyses. The overall thermohydraulic analysis is performed with a quasi three-dimensional code ldquoVINCENTArdquo and the boundary conditions are provided to Gandalf. In quench analyses, the two-dimensional ANSYS model was used to estimate the thermal diffusion from the heated conductor to the cold radial plate. The analyses show that the TF coils have sufficiently high minimum quench energy (around 300 mJ/cc-strand) against the mechanical disturbance and the disturbance due to a plasma disruption. The maximum temperature obtained in the quench analysis is allowable, for the condition of the detection voltage of 0.2 V, delay time of 2 s and the discharge time constant of 11 s. It is confirmed that the coils will be operated with reasonable margin and discharged without any damage if an unexpected quench occurs.