Comparison of Measurement And Modeling Of Current Profile Changes Due To Neutral Bean Ion Redistribution During TAE Avalanches in NSTX
Authors: Douglas S. Darrow, Neal Crocker, Niklolai N. Gorelenkov, Shigeyuki Kubota, Mario Podestà , Lei Shi, and Roscoe White
Abstract:
Brief "avalanches" of toroidal Alfvén eigenmodes (TAEs) are observed in NSTX plasmas with several different
n numbers simultaneously present. These affect the neutral beam ion distribution as evidenced by a concurrent
drop in the neutron rate and, sometimes, beam ion loss. Guiding center orbit modeling has shown that the modes
can transiently render portions of the beam ion phase space stochastic. The resulting redistribution of beam ions can
also create a broader beam-driven current profile and produce other changes in the beam ion distribution function.
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Published in: Plasma and Fusion Research, Volume 8, 2402119 (2013)
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Download PPPL-4929 (pdf 500KB / 3pp)
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