[Table of Contents]

Plasma and Fusion Research

Volume 8, 2402119 (2013)

Regular Articles

Comparison of Measurement and Modeling of Current Profile Changes due to Neutral Beam Ion Redistribution during TAE Avalanches in NSTX
Douglass S. DARROW, Neal CROCKER1), Niklolai N. GORELENKOV, Shigeyuki KUBOTA1), Mario PODESTÀ, Lei SHI and Roscoe WHITE
Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08453-0451, USA
1)
Department of Physics, University of California, Los Angeles, Los Angeles, CA, USA
(Received 9 December 2012 / Accepted 22 April 2013 / Published 15 November 2013)

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.

Keywords

Toroidal Alfvén eigenmode, neutral beam ion loss, beam driven current, guiding center orbit, orbit stochasticity

DOI: 10.1585/pfr.8.2402119

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This paper may be cited as follows:

Douglass S. DARROW, Neal CROCKER, Niklolai N. GORELENKOV, Shigeyuki KUBOTA, Mario PODESTÀ, Lei SHI and Roscoe WHITE, Plasma Fusion Res. 8, 2402119 (2013).