Design of JT-60SA Cryodistribution components

JT-60SA is a fusion experiment tokamak device with superconducting magnets to be built in Japan. As a unique feature of the JT-60SA cryodistribution system, the main cryogenic transfer line from the helium refrigerator directly inserts into the tokamak cryostat at 12.4 m height, and then it branches to 12 distribution units separately placed around the tokamak through headers in the cryostat. This configuration contributes to the maximization of plasma volume and installation flexibility for heating and measurement devices of plasma experiments but causes complicated cooling paths and severe conditions on a mechanical design due to the seismic event and the thermal contraction. In this work, we represent the system design of JT-60SA cryodistribution and several component designs in these severe conditions.