Speaker
Description
Alfvén eigenmodes (AEs), driven by energetic particles, are critical for understanding the stability and performance of magnetically confined plasmas. With the recent installation of the tungsten divertor in the KSTAR tokamak, significant changes to plasma equilibrium, edge profiles, and energetic particle dynamics necessitate predictive simulations to anticipate experimental results and guide operational strategies. This study investigates AE destabilization in KSTAR, focusing on the interplay between energetic particle (EP) drive and damping mechanisms under the altered plasma conditions, aiming to guide and interpret recent experiments.
The (Kinetic Alfven Eigen Solver) KAES code is utilized to accurately estimate damping rates of AEs, considering modified equilibrium and edge conditions, while the FAR3d code provides detailed insights into EP drive mechanisms by the beam-ions. By combining these approaches, we compare the relative contributions of EP drive and damping effects across a range of plasma scenarios, including variations in magnetic shear and edge profiles. This comprehensive analysis highlights key thresholds and sensitivities that interplay between damping mechanisms and EP drive in determining AE stability.
Preliminary results indicate significant sensitivity of AE stability to both EP distribution from NBIs and changes in edge conditions caused by the new divertor. These findings provide critical insights into mitigating AE-driven energetic particle losses, optimizing confinement, and improving overall plasma performance in the context of KSTAR’s upgraded divertor and evolving operational regime.
