[Table of Contents]

Plasma and Fusion Research

Volume 6, 2403109 (2011)

Regular Articles

Nonlinear Hybrid Simulations of Energetic Particle Modes in Realistic Tokamak Flux Surface Geometry
Andreas BIERWAGE, Yasushi TODO1), Nobuyuki AIBA, Kouji SHINOHARA, Masao ISHIKAWA and Masatoshi YAGI
Japan Atomic Energy Agency, Naka 311-0193, Japan
1)
National Institute for Fusion Science, Toki 509-5292, Japan
(Received 22 December 2010 / Accepted 15 April 2011 / Published 11 August 2011)

Abstract

First results from nonlinear simulations of energetic particle modes and the resulting transport of energetic ions using realistic tokamak geometry are presented and compared with results obtained with a shifted-circle model equilibrium and otherwise equivalent parameters. The modes excited in both cases have similar frequencies and mode structures and cause a similar amount of energetic ion transport during the first few hundred Alfvén times of the nonlinear evolution. The similarity in transport is interesting since it stands in contrast to the reduced linear growth rate and saturation level in the non-circular case: for the parameters chosen, both are reduced by a factor of 2 compared to the circular case. These results motivate further studies, including a verification of our results with other codes, a clarification of the mechanisms underlying the linear stabilization, and a detailed analysis of the mode activity and particle redistribution during the nonlinear evolution.

Keywords

tokamak, equilibrium geometry, shear Alfvén wave, energetic particle mode, nonlinear simulation

DOI: 10.1585/pfr.6.2403109

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This paper may be cited as follows:

Andreas BIERWAGE, Yasushi TODO, Nobuyuki AIBA, Kouji SHINOHARA, Masao ISHIKAWA and Masatoshi YAGI, Plasma Fusion Res. 6, 2403109 (2011).