Simulation of the ITER-CS coil operation including the effect of the ramp rate limitation

A model to simulate conductor performance of the Central Solenoid (CS) coil of the International Thermo-nuclear Experimental Reactor (ITER) is discussed. The conductor for the ITER-CS coil consists of multistage cables, where a non-uniform current distribution may be expected during operation which affects the stability of the conductor. A probable mechanism for the non-uniform distribution in a pulsed coil is flux loops between the strands or cable substages as the current is ramped up or down. A model for this distribution is presented. Simulations are then performed to quantify the effect of parameters, such as the unbalanced voltage of each strand caused by the flux loops, on the stability limit of the ITER-CS coil.