Performance Analysis of the ITER Poloidal Field Coil Conductors

Recent design changes to the ITER Poloidal Field (PF) coils and PF conductor layout have been implemented to give a greater operational window for low li (self-inductance) plasmas during burn, extend the operating window for plasmas with currents above 15 MA, and improve the plasma vertical stability control. In addition, the PF and CS (Central Solenoid) operating window has been updated leading to higher currents and peak fields in some of the PF coils. Altogether, this results in higher heat generation in the PF conductors due to AC losses. To confirm that the range of heat loads is acceptable for the PF conductors, a time-dependent thermo-hydraulic analysis of the PF coils has been performed with a model based on the GANDALF code. The deposited heat due to AC losses in the conductors, thermal radiation, thermal conduction, and nuclear heating are given as input data. The results show a moderate impact on minimum temperature margin of the PF conductors during the baseline scenario, stemming from the design modifications.