Stability performance of the DPC-TJ Nb/sub 3/Sn cable-in-conduit large superconducting coil

The DPC-TJ test coil was developed in the collaboration between the Japan Atomic Energy Research Institute (JAERI) and Toshiba for the Demo Poloidal Coil (DPC) project at JAERI to obtain key technologies required for the construction of superconducting coils of a fusion experimental reactor. The DPC-TJ is a 1-m-bore, 40-A/mm/sup 2/ forced-flow cooled superconducting coil wound with a double-walled 24-kA, 12-T (NbTi)/sub 3/Sn cable-in-conduit conductor. The DPC-TJ was tested to investigate stability performance at operating conditions between 15 kA, 2.3 T and 30 kA, 4.5 T. Another test was carried out with a 1/18 reduced-scale model of the DPC-TJ conductor to investigate stability margins at the designed field of 12 T. Results indicated the limiting current of the DPC-TJ was around 25 kA. The DPC-TJ coil was stably charged up to 30 kA without any normal transitions because only a small mechanical disturbance could occur in the newly developed type of conductor.<
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