Abstract Details
Abstracts
Author: Xueqiao Xu
Requested Type: Consider for Invited
Submitted: 2025-02-21 15:43:37
Co-authors: Jiangyi Li
Contact Info:
Lawrence Livermore National Laboratory
7000 East Ave
Livermore, CA 94550
US
Abstract Text:
Impurities profoundly influence plasma behavior, particularly in the edge and scrape-off layer (SOL) regions of tokamaks, where they shape transport dynamics and turbulence characteristics. This study advances traditional two-fluid and gyro-Landau-fluid (GLF) models by incorporating impurity effects with finite Larmor radius (FLR) corrections, providing a more comprehensive framework for impurity-driven transport. Heavy impurities, such as tungsten, exert a significant impact on turbulence and edge-localized mode (ELM) stability, even at low concentrations, due to their large mass and high charge states. By modifying vorticity evolution and gyrokinetic transport mechanisms, these impurities alter fundamental confinement properties. Our results highlight the critical role of impurity-induced polarization drift and the suppression of curvature-driven transport in high-Z species, which can influence both plasma stability and impurity retention. Through numerical estimates of impurity density ratios, gyro-radius effects, and charge states across different plasma regions, this work provides key insights into impurity transport mechanisms and their implications for fusion performance. Leveraging BOUT++ simulations and theoretical modeling, we offer new perspectives on impurity-induced turbulence and establish a foundation for improved impurity transport predictions in future fusion reactors. These findings underscore the urgent need for effective impurity management strategies to mitigate core contamination while optimizing radiation cooling in the divertor, contributing to the development of predictive impurity transport models for reactor-scale magnetic confinement fusion.
Characterization: 2.0
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