Plasma and Fusion Research

Volume 4, 051 (2009)

Regular Articles

Rotational Stabilization of Resistive Wall Mode on JT-60U
Go MATSUNAGA, Manabu TAKECHI, Nobuyuki AIBA, Genichi KURITA, Yoshiteru SAKAMOTO, Yoshihiko KOIDE, Akihiko ISAYAMA, Takahiro SUZUKI, Takaaki FUJITA, Naoyuki OYAMA, Takahisa OZEKI, Yutaka KAMADA and JT-60 Team
Japan Atomic Energy Agency, Naka 311-0193, Japan
(Received 24 July 2009 / Accepted 14 August 2009 / Published 5 November 2009)

Abstract

We have carried out experiments to clarify the stabilizing effect of a plasma rotation on the resistive wall mode (RWM) that could limit the achievable-βN in high-βN plasmas above the no-wall ideal βN-limit. On JT-60U plasma rotations are controlled using neutral beams with varying combinations of net torque input while keeping βN constant. The RWM is destabilized as the plasma rotation is being reduced. Detailed measurements of the mode structure revealed that the RWM has a global structure that rotates with the order of the resistive wall time. In these experiments, it is found that the critical toroidal rotation speed for the RWM stabilization is less than 1% of the Alfvén speed. Moreover, the critical rotation does not strongly depend on βN. The results suggest that high-βN operation up to the ideal wall βN-limit could be possible by suppressing the RWM with a slow plasma rotation in fusion reactors.

Keywords

resistive wall mode, plasma rotation, JT-60U

DOI: 10.1585/pfr.4.051

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This paper may be cited as follows:

Go MATSUNAGA, Manabu TAKECHI, Nobuyuki AIBA, Genichi KURITA, Yoshiteru SAKAMOTO, Yoshihiko KOIDE, Akihiko ISAYAMA, Takahiro SUZUKI, Takaaki FUJITA, Naoyuki OYAMA, Takahisa OZEKI, Yutaka KAMADA and JT-60 Team, Plasma Fusion Res. 4, 051 (2009).