The TPX magnet R&D program

A unique feature of the magnet system for the Tokamak Physics Experiment (TPX) is that all the magnets are superconducting. With the exception of the outer poloidal coils, the magnet system uses Nb₃ Sn cable-in-conduit conductor; the outer poloidal coils use Nb-Ti cable-in-conduit conductor. A Research and Development program is needed to ensure that the materials, processes, and systems are available to support the fabrication and operation of these magnets. We describe our plans for R&D in the areas of: conductor strand and sheath development, insulation materials and configuration, conductor forming, curing, and impregnation techniques, and quench detection methods and techniques. Since a significant portion of the TPX magnet system design and fabrication will be done in industry, a division of the magnet R&D effort between industry and the National Laboratories is proposed. A close liaison is maintained with the ITER magnet R&D program, and TPX will make use of ITER results whenever possible