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Title: Properties of Alfven Eigenmodes in the TAE range on the National Spherical Torus Experiment-Upgrade

Technical Report ·
DOI:https://doi.org/10.2172/1089858· OSTI ID:1089858

A second Neutral Beam (NB) injection line is being installed on the NSTX Upgrade device, resulting in six NB sources with di erent tangency radii that will be available for heating and current drive. This work explores the properties of instabilities in the frequency range of the Toroidal Alfv en Eigenmode (TAE) for NSTX-U scenarios with various NB injection geometries, from more perpendicular to more tangential, and with increased toroidal magnetic eld with respect to previous NSTX scenarios. Predictions are based on analysis through the ideal MHD code NOVA-K. For the scenarios considered in this work, modi cations of the Alfv en continuum result in a frequency upshift and a broadening of the radial mode structure. The latter e ect may have consequences for fast ion transport and loss. Preliminary stability considerations indicate that TAEs are potentially unstable, with ion Landau damping representing the dominant damping mechanism

Research Organization:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
DE-ACO2-09CH11466
OSTI ID:
1089858
Report Number(s):
PPPL-4868
Country of Publication:
United States
Language:
English