Status of the poloidal field system design for the International Thermonuclear Experimental Reactor

Configuration, design features and performance characteristics of the poloidal field (PF) coil system of the International Thermonuclear Experimental Reactor (ITER) are described. The PF coil system is completely superconducting and comprises a central solenoid (CS) and six ring coils. The CS is bucked structurally against the TF to provide maximum flux swing for plasma initiation and inductive current drive during fusion burn. Total system flux swing is 635 Wb: this flux swing and the associated equilibrium and control fields are sufficient for a 1000-s fusion burn with plasma current of 25 MA. The PF system also provides for robust control of the plasma shape and single-null divertor configuration throughout the operational scenario, and for dynamic expansion and contraction the plasma during the current initiation and termination phases. Details of the operational scenario and discussion of the effects of variations in the plasma profile parameters are presented