2024 – Obtaining and optimizing n=1 RMP Suppression in DIII-D

Obtaining and optimizing n=1 RMP Suppression in DIII-D

2024 Research Campaign, Transient Control

Purpose of Experiment

The objective of this experiment is to achieve the first observation of robust suppression of Edge-Localized Modes (ELMs) with n=1 resonant magnetic perturbation (RMP) fields in DIII-D, and record the corresponding changes in the pedestal structure. Sustained ELM suppression with n=1 fields has never been achieved in DIII-D, while being the standard operating mode for KSTAR [Jeon PRL 2012] and EAST [Sun PRL 2016]. Thus, this experiment will enable a new datapoint in the existing n=1 ELM suppression dataset, allowing for more consistent cross-machine comparisons in access criteria, which is essential for physical understanding and for extrapolating the RMP technique to the reactor scale.

Experimental Approach

GPEC simulations have found a potentially favorable coil configuration for DIII-D plasmas that enables a higher edge-to-core resonant flux ratio, which should enable the plasma to enter full and sustained RMP ELM suppression without 2/1 locked modes.