The Toroidal Field Model Coil (TFMC) is one of the seven large ITER Research and Development (R&D) projects. Its objective is to develop and demonstrate the superconducting magnet technology to a level that will allow the ITER Nb3Sn toroidal field coils to be built with confidence. The current of 80 kA reached in this superconducting coil represents a world record.

The TFMC was built by a European industrial consortium under the supervision of EFDA. The first tests were carried out by the joint European Research and Development Centre “Forschungszentrum Karlsruhe” (FzK) in Germany. In this phase, the TFMC was installed as a single coil in the TOSKA facility and tested to its maximum current of 80 kA, which was reached for the first time on July 25, 2001. Up to the end of the year 2001, the TFMC was energized 19 times to its maximum current with eight safety discharges made (at this current level) and five following intentionally induced quenches. The maximum magnetic field of 7.8 T and the maximum temperature of 8.7 K were in agreement with the expected values, according to the previous tests of the superconductive strands used for the conductor.


. Central Solenoid Model Coil – L1

. Toroidal Field Model Coil – L2

. Vacuum Vessel Sector – L3

. Blanket Module – L4

. Divertor Cassette – L5

. Blanket Module Remote Handling – L6

. Divertor Remote Handling – L7

Fifteen joints have been made in the path of the superconducting current between the positive and the negative warm end of the current leads. In the second test campaign, due to start in summer 2002, the already existing European Large Coil Task (LCT) coil will be used as a background field coil to test the mechanical performance of the TFMC. The two superconducting coils have been assembled back to back with a strong intercoil steel structure. At present the TFMC/LCT assembly is being installed in the cryostat of the TOSKA facility and the hydraulic and electrical connections are being finalised. During the second campaign, the maximum magnetic field will increase to about 9.6 T, although the maximum current in the TFMC will be reduced to 70 kA. EFDA Newsletter will follow the tests at the TOSKA facility and will report the results to you in forthcoming issues.

Features of TFMC
Height 3.79 m
Width 2.83 m
Diameter 0.78 m
resistances 1.1 nΩ – 1.9 nΩ
Total weight 35 t

For more information see: EFDA Newsletter
Vol. 3/Dec. 2001 and