The Test of the EURATOM LCT Coil at the Outermost Limits at 1.8 K as Example of Single Coil Testing of D Shaped Toroidal Field Coils

摘要

The relevant testing of D shaped magnets was an intensively discussed item in the seventies. These discussions led to the initiation of the "Large Coil Task". The EURATOMLCT coil was the contribution of the European Union to this experiment. After successful testing the excellent performance encouraged to go up to the outermost achievable boundary. The coil design was compatible with forced flow operation at 1.8 K in a single coil test when an effective reinforcement of the mechanical structure was applied. Beside this, cooling of a large magnet by forced flow He II was a challenging task, too. The EURATOM LCT coil achieved thereby the predicted quench current of 19.4 kA at 11 T. The mechanical reinforcement structure worked excellently without any backlash and in full agree-ment with the finite element chaculations. The experiment demonstrated successfully that a D shaped coil can be tested as free standing single coil if a suitable reinforcement of the structure is applied. This is an important result for pre-testing single D shaped coils at rated or higher current values to demonstrate that the performance is achieved prior to installation in the toroidal configuration. A conceptual check of the application for the ITER toroidal field coils was performed.