Control and Instrumentation for the ITER Magnet System

The ITER superconducting coil system consists of 18 Toroidal Field coils, six Poloidal Field coils, six Central Solenoid modules, 18 Correction Coils and their feeders. An extensive measurement and control system is required to monitor and control these coils and feeders for safety and optimal operational availability. For each coil, both current and supercritical helium are supplied from external systems and are controlled from a central system as part of the regular operation with plasma pulses. These allow adjustment of currents and, through a virtual model of the coil thermohydraulic system continuously benchmarked to the external instrumentation, allow smoothing of the cryoplant loads and optimization of the plasma pulse rate. Quench detection is provided as a separate, stand alone system. Finally, regular monitoring of the electric insulation system inside the coils is performed to detect incipient problems before serious damage can develop