[Table of Contents]

Plasma and Fusion Research

Volume 8, 2403090 (2013)

Regular Articles

Simulation Study of Alfvén-Eigenmode-Induced Energetic Ion Transport in LHD
Seiya NISHIMURA, Yasushi TODO, Donald A. SPONG1), Yasuhiro SUZUKI and Noriyoshi NAKAJIMA
National Institute for Fusion Science, Toki 509-5292, Japan
1)
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
(Received 22 November 2012 / Accepted 22 April 2013 / Published 19 June 2013)

Abstract

The interaction between toroidal Alfvén eigenmode (TAE) and energetic ions in the Large Helical Device (LHD) is investigated using a reduced version of the MEGA code that implements a realistic equilibrium magnetic field with the HINT code and corresponding TAE profile with the AE3D code. In simulations, the linear growth rate of TAE amplitude is proportional to energetic ion density; consequently, the nonlinear saturation level of the TAE amplitude is enhanced by the increase in the energetic ion density. Energy transfer analysis is performed to clarify destabilization and saturation mechanisms of the TAE and to identify resonant energetic ions. An analysis of test particles in the electromagnetic field perturbed by the TAE shows that the magnitude of fluctuations in the energetic ion orbits is proportional to the square root of the TAE amplitude. Our results qualitatively reproduce the radial transport of energetic ions by the TAE in the LHD.

Keywords

Alfvén eigenmode, energetic ion, three-dimensional equilibrium, hybrid simulation, particle-in-cell method

DOI: 10.1585/pfr.8.2403090

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Publisher's Note

This article was originally published with a typographical error in the page 2403090-6. The article has been corrected as follows:
P. 2403090-6, Ref.[2]: "Nucl Fusion 51, 083030 (2011)" -> "Nucl. Fusion 46, S911 (2006)".

This paper may be cited as follows:

Seiya NISHIMURA, Yasushi TODO, Donald A. SPONG, Yasuhiro SUZUKI and Noriyoshi NAKAJIMA, Plasma Fusion Res. 8, 2403090 (2013).