ASIPP successfully qualified first toroidal field conductor sample

China's first toroidal field conductor sample (TFCN1) was successfully tested at the SULTAN test facility in Switzerland. The sample exhibited good and stable performances with a current sharing temperature of the order of 6.9 K at 68 kA and a background field of 10.78 T, even after 950 energization cycles.

These current sharing temperatures, which determine the operating margin of the magnet, are among the highest ever recorded on toroidal field conductor samples at SULTAN and qualify the strand type and the cable/jacket design and process combination that were used to manufacture the sample. This performance qualification is a pre-requisite to the execution of the Procurement Arrangement and will enable the Chinese Domestic Agency to launch the production of its 7.5-percent share of the toroidal field conductor, corresponding to 5 regular (760 m) and 5 side (415 m) double pancake unit lengths.

The Institute of Plasma Physics of the Chinese Academy of Sciences (ASIPP), located in Hefei, has taken charge of the ITER superconductor technology development in China based on the technologies developed during the construction of the EAST superconducting tokamak. Cooperating with leading institutes and companies throughout China and in close collaboration with the ITER Organization, ASIPP has succeeded in developing a baseline technology for ITER toroidal field conductor manufacture.

The toroidal field conductor for the SULTAN sample was produced in 2008, and was shipped to Sultan in October 2008. The Cr-plated Nb3Sn strands and Cr-plated Cu strands for TFCN1 were supplied by OST. The cable was manufactured by Baosheng Science and Technology Innovation Inc. The austenitic stainless steel tube for the jacket was produced by Baoshan Iron & Steel Co., Ltd, while cable insertion and conductor compaction were carried out by ASIPP. Conductor sample heat treatment, assembly and instrumentation were carried out at Sultan.