Integrated 3D-edge Long-pulse Tokamak Scenarios ¿ Extended with Core Instability and Transport Control

This project extends the predictive capabilities of non-axisymmetric (3D) field physics with integrated scenario optimizations to demonstrate the scientific feasibility of 3D magnetic perturbations for transport and instability control in long-pulse high-performance tokamak plasmas. A key example of this is the suppression of the edge-localized-modes (ELMs) by resonant 3D magnetic perturbations (RMPs). ELMs constitute a major challenge to the operation of fusion-grade tokamak plasmas such as ITER due to the large transient heat loads they deliver to plasma facing components (PFCs). US scientists have pioneered the development of the 3D-field approach to ELM control since its first discovery and have a crucial role in exporting the technique to international facilities such as the KSTAR tokamak in Korea, the EAST tokamak in China, and the AUG tokamak in Germany. Recent international collaborations have enabled the project team to compile comprehensive 3D databases, develop testable criteria for the accessibility and threshold conditions of ELM suppression, improve understanding of underlying particle transport for predicting pedestal profile modifications and heat flux to PFCs, and adaptively control 3D fields to restore confinement under ELM suppression. These recent accomplishments have exposed opportunities for the US scientists to resolve remaining challenges, such as the compatibility of 3D ELM suppression with core optimized scenarios as well as heat loads to PFCs for long pulses. Enhanced physics models, databases, and experimental analysis infrastructures developed by this project team will be all leveraged utilizing the strong partnerships among the multi-institutional US groups and international collaborators. Predictive capabilities for 3D edge perturbations, transport, and ELM suppression will be validated over international databases with analysis utilizing US cutting-edge 3D simulations. Intelligent control algorithms for the 3D field operational windows and associated profile alterations will be developed and integrated into TRANSP for long pulse optimization. This novel '3D TRANSP' will be tested and refined on KSTAR with the new tungsten divertors, in preparation for ITER applications. In parallel, the 3D field physics basis will be extended to optimize fast ion losses and heat flux to divertors. Understanding of turbulent transport across 3D magnetic topologies including edge and core island chains as well as stochastic field lines will also be extended. All these developments will be integrated to establish optimized long pulse scenarios with 3D fields in KSTAR. The predictive 3D scenario optimizations will be then combined with real-time, actively probing, adaptive controllers to demonstrate ELM-free H-mode scenarios in KSTAR for long pulses of up to 300s with ?? N >2.0, minimal core MHD, maximized confinement, and minimized heat loads to plasma facing components.