Improvements to the ITER Magnets to Extend the Plasma Operating Window

The ITER magnet system, particularly the Poloidal Field Coils (PFC) and Central Solenoid Coils (CSC), was originally designed to drive, confine and stabilise a set of plasmas about a baseline of a reference 15MA 400s inductive burn, with capability for inductive short burn at currents up to 17MA and 10MA non-inductive plasmas depending on the plasma parameters that can be achieved.

Recent assessments of experimental data and improved plasma modelling have identified some constraints in the 2001 design that may limit the range of plasmas that can be generated in ITER. The constraints are a mixture of coil superconducting performance, structural and electrical limits, and concern both the accuracy of the formation of the plasma configuration (including the position of the separatrix lines in the divertor) and the stabilisation of the plasma position.