Engineering design status of the KSTAR TF coil structure

The toroidal field (TF) magnet system of Korea Superconducting Tokamak Advanced Research (KSTAR) device consists of 16 superconducting coils enclosed in steel cases. The TF cases are wedged along the inboard straight legs to sustain in-plane centering forces. The inter-coil structures contain adjustable shear keys and conical bolts to provide pre-loading in toroidal direction and to resist in-plane and out-of-plane forces, which are the most critical loads on the TF magnet system. For effective cooling of the TF case, a pad-type cooling channel has been designed to ensure structural and thermal stability. In order to investigate the structural integrity and to increase the structural reliability of the KSTAR magnet system, structural analyses have been conducted. From the analysis results, it has been found that the TF magnet structure can safely withstand the reference scenario operations.