Quench Detection in the ITER Magnet System

The quench detection system in ITER superconducting magnet systems is a real challenge for the poloidal field (PF) system and the central solenoid (CS) due to their fast-pulsed operation. An existing CEA code allowing very precise magnetic field calculations in tokamaks (Traps) has been upgraded (TrapsAv) to calculate the inductive voltages induced across any coil sub-element during a plasma scenario. The envisaged primary detection system is based on voltage measurements. For the CS, a detection system is proposed and discussed based on the central difference average balance of 3 neighboring double pancakes. For the TF system, the presently considered compensation circuit in ITER is a strip co-wound on to the conductor. A simple analytical calculation is proposed to estimate the voltage during a plasma disruption or during the scenario across the co-wound strip and across the conductor as well, due to the toroidal component of the plasma current.