Abstract Details
Abstracts
Author: Jace C Waybright
Requested Type: Poster
Submitted: 2025-03-13 15:07:49
Co-authors: Y. Lee, J.K. Park
Contact Info:
Princeton Plasma Physics Laboratory
100 Stellarator Road
Princeton, New Jersey 08540
United States
Abstract Text:
Non-axisymmetric magnetic perturbations can have a significant effect on tokamak performance as observed with error fields or applied resonant magnetic perturbations (RMPs). These perturbations induce complex responses near the plasma resonant surface, which can be characterized in the linear regime by the inner-layer Δ. One such response is field penetration, which occurs when the external field is able to create magnetic islands, which otherwise would be screened. A plasma’s natural rotation is known to stabilize against this magnetic island formation, however when the external field passes what is called the field penetration threshold, the rotation is arrested and results in locked modes. We apply a two-fluid drift-MHD model to obtain analytic estimates for the inner-layer Δ and field penetration threshold while including some previously neglected effects, including electron viscosity, ion parallel flow, and neoclassical toroidal viscosity (NTV). A recent numerical study has suggested a significant impact of ion parallel flow on the plasma response in the case of high-β; specifically, a shift in the resonance location for Δ. Here, we reproduce this effect analytically in certain parameter regimes to estimate its effect on the scaling of Δ and the field penetration threshold.
Characterization: 1.0
Comments: