Abstract Details
Abstracts
Author: Dmitri M Orlov
Requested Type: Consider for Invited
Submitted: 2024-04-11 15:48:57
Co-authors: T.B. Cote, E.C. Howell, V.E. Khavin, S.K. Kim, Z. Lin, J.K. Park, X.Wei, S.M. Yang
Contact Info:
UC San Diego
9500 Gilman Drive #0417
La Jolla, CA 92093
USA
Abstract Text:
Addressing the challenge of long-pulse ELM suppression involves managing the interaction between heat, particle fluxes, and plasma-facing components, while reducing the influx of impurities into the core plasma. Central to overcoming this challenge is the understanding of transport in presence of 3D fields that modify the magnetic topology at the plasma's edge and core. This work highlights outcomes from the latest experiments in KSTAR's H- and L-mode plasmas, particularly focusing on discharges #19118, which is characterized by a pronounced 2/1 magnetic island, and #30306, demonstrating RMP ELM suppression, to evaluate the accuracy of current plasma response (M3D-C1, NIMROD) and turbulent transport (GTC) simulations.
During the L-mode discharge #19118, observations indicated increased turbulence near the 2/1 magnetic island's X-point. This observation supports the hypothesis of ExB convection mechanism’s role across the island's X-point. The experimental results are further validated by plasma response models, which accurately predicted the magnetic island width, as confirmed by ECEI measurements. Turbulent transport simulations showed the extent of turbulence spread across the magnetic surface by using data from the plasma response models for both the axisymmetric scenario and the n=1 magnetic island case.
The H-mode discharge #30306 showcased successful ELM suppression through the use of rotating Edge-localized RMPs. This was backed by comprehensive diagnostics, allowing for thorough validation of the simulation models from plasma response to detailed 3D heat flux and fast ion transport analysis. The success of simulations bolsters our confidence in the predictive power of our current models regarding transport processes in the presence of 3D fields and magnetic islands, offering insights into the mechanisms behind RMP ELM suppression.
Work supported by US DOE under DE-FG02-05ER54809, DE-SC0020413, DE-SC0020298, DE-SC0021185, DE-SC0018287, and DE-AC02-09CH
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