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Roles of Toroidal Rotation at the Plasma Edge, Toroidal Field Ripple and Configuration on ELMs in the JT-60U Tokamak

Kensaku KAMIYA, Hajime URANO, Naoyuki OYAMA and Yutaka KAMADA

Japan Atomic Energy Agency

(Received 13 December 2006 / Accepted 24 January 2007 / Published 7 March 2007)

Abstract

Recent experimental studies are presented regarding ELMy H-mode plasma having Type-I Edge Localized Modes (ELMs) in the JT-60U. Toroidal rotation scan experiments in inward-shifted, small-volume plasma show that the ELM energy loss decreases as the toroidal rotation at the plasma edge increases in the direction counter to the plasma current. Specifically for a large volume plasma having a toroidal field ripple of ∼2% at the plasma edge, small Type-I ELMs are observed whose ELM energy loss normalized by the pedestal stored energy is smaller than that of an acceptable ELM size in the ITER. However, the pedestal pressure tends to decrease when plasma volume increases. No remarkable effect of reduced toridal field ripple due to the installation of Ferritic Steel Tile (FSTs) inside the vacuum vessel on the JT-60U on ELMs for large volume plasma is seen in the ELM energy loss normalized by the pedestal stored energy. These new findings suggest that the toroidal field ripple itself may not directly affect the normalized ELM energy loss, and that toroidal rotation at the plasma edge as well as plasma configuration might play important roles in the prediction of ELM size in future devices.

Copyright (c) 2007 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

ELM, H-mode, tokamak, ITER, divertor, plasma rotation, toroidal field ripple, plasma configuration

DOI: 10.1585/pfr.2.005

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References

• [1] ITER Physics Basis, Nucl. Fusion 39, 2175 (1999).
• [2] A. Loarte et al., Nucl. Mater. 313-316, 962 (2003).
• [3] T.E. Evans et al., Phys. Rev. Lett. 92, 235003 (2004).
• [4] H. Urano et al., Plasma Phys. Control. Fusion 45, 1571 (2003).
• [5] A.W. Degeling et al., Plasma Phys. Control. Fusion 45, 1637 (2003).
• [6] C.M. Greeneld et al., Phys. Rev. Lett. 86, 4544 (2001).
• [7] W. Suttrop et al., Plasma Phys. Control. Fusion 46, A151 (2004).
• [8] Y. Sakamoto et al., Plasma Phys. Control. Fusion 46, A299 (2004).
• [9] N. Oyama et al., Nucl. Fusion 45, 871 (2005).
• [10] Y. Kamada et al., Plasma Phys. Control. Fusion 44, A279 (2002).
• [11] Y. Koide et al., Plasma Phys. Control. Nucl. Fusion Res. 1, 777 (1992).
• [12] M. Yoshida et al., Plasma Phys. Control. Fusion 48, 1673 (2006).
• [13] H. Urano et al., Plasma Phys. Control. Fusion 48, A193 (2006).
• [14] H. Urano et al., Proc. 21st IAEA Fusion Energy Conf., Chengdu (China), 2006, appear in CD-ROM paper IAEA-CN-149/EX/5-1.
• [15] K. Shinohara et al., Proc. 21st IAEA Fusion Energy Conf., Chengdu (China), 2006, appear in CD-ROM paper IAEA-CN-149/FT/P5-32.
• [16] P.B. Snyder et al., Plasma Phys. Control. Fusion 46, A131 (2004).
• [17] G. Federici et al., Nucl. Mater. 313-316, 11 (2003).
• [18] G. Federici et al., Plasma Phys. Control. Fusion 45, 1523 (2003).
• [19] J.G. Cordey et al., Plasma Phys. Control. Fusion 39, B115 (1997).
• [20] P.B. Snyder et al., Nucl. Fusion 44, 320 (2004).
• [21] N. Aiba et al., Proc. 21st IAEA Fusion Energy Conf., Chengdu (China), 2006, appear in CD-ROM paper IAEA-CN-149/TH/P8-1.

This paper may be cited as follows:

Kensaku KAMIYA, Hajime URANO, Naoyuki OYAMA and Yutaka KAMADA, Plasma Fusion Res. 2, 005 (2007).