Analysis of losses in ITER joints in a varying parallel field

One of the options for a design of a Central Solenoid in ITER and other tokamak machines is pancake wound modules. In this configuration joints have to be placed in maximum magnetic field with high changing rate. Joints should be designed to have at least the same or larger temperature margin as that for the conductor in the same field. We show that joints in parallel field can be designed to meet this requirement along with reasonably low DC resistance. Losses in parallel field are calculated and design features which can suppress AC losses without increasing DC resistance are discussed. Recommendations for low loss, low DC resistance joints are made.