Updating the design of the feeder components for the ITER magnet system

Yoshida, Kiyoshi; Takahashi, Yoshikazu; Isono, Takaaki; Mitchell, N.*

The ITER superconducting magnet system stores energy of 50 GJ during plasma operation, and generates an average heat load of 23 kW at 4 K to cryoplant. The helium is distributed to the coil through 30 separate feeder lines. The feeders also contain the electrical supplies to the coil and are integrated into the current lead transition to room temperature. The interface components between the coils and the service facilities (power supply and cryogenic plant) consist of the in-cryostat feeders, the cryostat feedthroughs, and the coil terminal boxes (CTBs). The cryostat feedthroughs with S-bend boxes allow thermal contraction of the magnet system. The layout of the in-cryostat feeders takes into consideration routing restrictions in the cryostat and initial assembly with other Tokamak components. The forced-flow-cooled current leads with a conventional copper heat exchanger in the CTBs are adapted to fit in the limited space in the building. This paper presents the latest design concept and parameters of the feeder components.