Search

The aims of the TF Model Coil are to test the manufacturing feasibility of the ITER TF magnet concepts, to assess the reliability of the fully integrated system by dedicated testing and to qualify the quality assurance and the testing methods. The 3.8 m long racetrack shaped TFMC will be tested in the TOSKA facility at Karlsruhe in a configuration using the Euratom LCT Coil to provide in-plane and out-of-plane loads, relevant to the ITER coils.

A 30 kA/23 kV current lead cooled by forced-flow supercritical helium has been developed at KfK. It allows position independent installation and well controlled operation which would be advantageous for operation of all kind of super-conducting forced-flow cooled magnets. The design of the lead is described in this paper. The main feature is the insertion of [Nb.sub.3]Sn wires inside the conductor of the heat exchanger allowing the operation at minimum mass flow in a wide current range. Measurement results are presented for steady-state operation up to 30 kA, for short time operation up to 50 kA, for pulsed operation up to [+ or -] 1000 A at 10 Hz, and for simulation of loss of mass flow. A high-voltage test up to 28 kV DC has been done. The mass flow rate normalized to current is about 0.055 g/(s-kA) for 15 to 30 kA proving the effectiveness of the [Nb.sub.3]Sn inserts. Comparison to numerical calculations shows good agreement allowing extrapolation for the design of leads for currents up to 80 kA for ITER model coil tests in the TOSKA test facility at KfK.