Residual Inductive Voltages in the Quench Detection Loops of the ITER TF Coil During Testing in the ITER Magnet Cold Test Bench

While the assembly of the ITER device is progressing, a Magnet Cold Test Bench (MCTB) is also under preparation to test some of the ITER superconducting coils at 4 K up to nominal current before their installation in the pit. In this context calculations are performed to estimate the residual inductive voltages in the quench detection loops of the TF coils during the test scenarios. These residual inductive voltages are defined as the difference between the turn and Co-Wound-Tape (CWT) voltages appearing during ramping operation. These residual voltages need to be known as they cannot be avoided and because they need to be smaller than the resistive voltage developing during a quench to allow its detection. In particular, the case of a fast discharge is investigated, which represents the most severe transient operation expected for MCTB, generating the largest possible residual inductive voltages. Once validated against the MCTB tests, the models used to predict these residual inductive voltages in the ITER TF coils, can be applied to predict these voltages during a ITER plasma pulse. This will allow the assessment by which margin quenches can be detected in the ITER TF coils during plasma operation.