Expected Error Fields in ITER: a full-device source model and strategies for safe operation

ITER coil assembly tolerances are re-evaluated using the modern understanding of coupling to least-stable plasma modes and an updated center-line-traced model of ITER's coil windings. This reassessment finds the existing assembly tolerances to be conservative.[CP1] This is done through a statistical, linear study of $n=1$ error fields (EFs) due to tilted, shifted displacements and nominal windings of central solenoid and poloidal field coils within tolerance. We also show that a model-based correction scheme remains effective even when metrology quality is sub-optimal, and compare this to projected empirical correction schemes. We show an analysis of the necessity of error field correction (EFC) for daily operation in ITER using scaling laws for the EF penetration threshold[CP2] . We then consider the predictability of EF dominant mode overlap across early planned ITER scenarios and, as measuring EFs in high power scenarios can pose risks to the device, the potential for extrapolation to the ITER Baseline Scenario (IBS). We find [CP3] that carefully designing a scenario matching currents proportionally to those of the IBS is far more important than plasma shape or profiles [CP4] [MOU5] in accurately measuring an optimal correction current set.