Design and analysis of the ITER TF feeder dry box

The dry box (DB) is the transition section from the superconducting cables to the conventional ones; it houses the warm end of the high temperature superconducting current lead (HTS-CL) and the water-cooled cables, as well as the joint between them. The main function of the DB can be divided into two types, the thermal function provides a dry environment for the HTS-CL to prevent condensation on the warm end of the lead, which comes from the excess helium gas cooling power of the lead; on the other hand, the mechanical function supports the heavy joint and the water-cooled cables, which should be easy to connect and remove, meanwhile the strengthen should be enough. Therefore, the chamber is filled with hot dry air with positive pressure to the atmosphere outside, the natural and forced convection, as well as the electrical heater and thermal insulation layer are discussed. This paper describes these efforts.