Heating surge and temperature oscillation in KSTAR PF and TF coils for plasma disruption under continuous plasma discharging conditions

The operating characteristics in the poloidal field (PF) and toroidal field (TF) coils of KSTAR (Korean Superconducting Tokamak Advanced Research) for given operating scenarios are analyzed. In order to control the plasma shaped in KSTAR to realize the thermal nuclear fusion reaction, the operating currents in PF coils are controlled with high ramp rate with respect to time. The induced currents in the support structure and cryostat generate high eddy losses. They also produce a large hysteresis, eddy and coupling losses in superconducting PF and TF coils. The supercritical helium with high velocity through the cable-in-conduit-conductor (CICC) removes the heat load to keep the temperature of superconducting cable lower than its current sharing temperature. The maximum temperature rises in PF and TF are calculated under the continuous operating scenario. The simulation shows that the maximum temperatures in TF and PF are about 5.7 K and 5.9 K, respectively.