KSTAR poloidal and toroidal field design

Abstract

The Korean Superconducting Tokamak Advanced Research (KSTAR) will have superconducting magnets for both the poloidal field (PF) coils and the toroidal field (TF) coils. The physical arrangement of the PF set has 14 coils external to the TP coils. The analysis of the equilibrium flexibility of the KSTAR PF system determines the coil currents required to maintain prescribed equilibrium configurations over the desired range of operational parameters specified in I/sub p/ (q/sub 95/), /spl beta//sub N/, and l/sub 1/(3). Constraints on the plasma separatrix and the flux linkage through the geometric center of the plasma are specified for the free boundary equilibrium calculations. In order to eliminate the remaining freedoms the coil current distribution is regularized (smoothed) by minimizing the quantity /sup ncoil//spl Sigma//sub j=1/ (i/sub j///spl Delta/Aj)/sup 2/ where /spl Delta/A/sub j/ is the area of each PF coil. The ripple magnitude due to the finite number of TF coils and the size of the port for the neutral beam injector determine the number, size, rand shape of TF coils. Two ripple criteria for a shaped plasma are used for types of ripple transport. The current design of the TP coil, 16 coils and D-shape, is big enough to satisfy requirements on the ripple magnitude at the plasma and to provide an adequate access for tangential NB injection.