Synthetic Diagnostic Assessment of ITER ECE Performance for NTM Detection

A synthetic diagnostic for the ECE system has demonstrated low-latency detection of neoclassical tearing modes (NTM) and was used to inform radiometer design and optimization. Magnetic islands associated with the 2/1 NTM and as small as 3 cm are shown to be detectable, with detection latency on order of 100s of ms. These studies used a novel helical-flux perturbation model to simulate NTMs. It incorporates the most up-to-date models of island growth and rotation in an ITER plasma, as well as relativistic effects on ECE. The synthetic diagnostic is incorporated into a high-fidelity plasma simulator under development at ITER. The inclusion of the synthetic ECE diagnostic and NTM modeling into an ITER network compatible workflow will allow self-consistent end-to-end testing of ITER IMAS database plasma scenarios. From ramp-up to ramp-down, the expected ECE is modeled for scenarios spanning the ITER operational range. The results inform diagnostic capabilities and operation and provide quantitative guidance for configuration and NTM mitigation strategies.