The ITER toroidal field model coil (TFMC)

The TF coils for ITER (ITER, Final Design Report, December 1997) will use t he concept of a circular thin walled Nb3Sn cable in conduit superconductor completely enclosed in an insulated groove in steel plates to form the coil pancakes. These are then stacked together to form the winding pack support ed by a steel case. The concept is being demonstrated by the fabrication of a TFMC (E. Salpietro et al., Construction of a Toroidal Field Model Coil ( TFMC) for ITER, MT-15 Fifteenth International Conference on Magnet Technolo gy, Oct 20-24, 1997, Beijing, China; R. Maix et al., Manufacture of the ITE R TF model coil (TMFC), Poster P1-217) with a bore of 1.4 x 2.5 m, a peak f ield of 8.77 T and a total current of 7.8 MAT. The coil will be tested duri ng 1999 in the TOSKA facility at FZK, Karlsruhe, using the EURATOM LCT coil to provide an external field system. The objectives of the TFMC are as fol lows: 1. to develop and verify the full scale TF coil manufacturing techniques, i n particular the following features: plate manufacturing (forming the grooves); fitting the conductor in the groove after heat treatment and insulation (i. e. predictable geometry change); closing the groove with a cover plate and plate insulation; fitting the winding into the case, gap filling and case closure; 2. to establish realistic manufacturing tolerances; 3. to bench-mark methods for the ITER TF coil acceptance tests, including i nsulation and impregnation process; 4. to obtain information on the coil's mechanical behaviour, operating marg ins and in-service monitoring techniques, particularly for the insulation q uality over fatigue cycles. (C) 1999 Elsevier Science S.A. All rights reser ved.