Regular Articles

Full Text / References

Plasma Rotation Measurements by Passive Spectroscopic Method in the HYBTOK-II using a Dynamic Ergodic Divertor

Yu HASEBE, Masaaki OKAMOTO, Shin KAJITA¹⁾, Noriyasu OHNO²⁾ and Shuichi TAKAMURA³⁾

Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan

1)

Japan Atomic Energy Agency, Naka 311-0193, Japan

2)

EcoTopia Science Institute, Nagoya University, Nagoya 464-8603, Japan

3)

Department of Electronics, Aichi Institute of Technology, Toyota 470-0392, Japan

(Received 16 November 2007 / Accepted 6 February 2008 / Published 1 August 2008)

Abstract

Plasma rotation or its shear is important in the formation of a transport barrier. It is believed that a rotating helical magnetic field generated by a dynamic ergodic divertor (DED) can generate a rotational torque in tokamak plasmas, and therefore control the rotation profiles. To measure the plasma rotations and investigate the effect of DEDs on them, we developed a passive spectroscopic measurement system for the small tokamak HYBTOK-II. A spontaneous toroidal plasma rotation in the co-current direction and poloidal plasma rotation in the electron diamagnetic drift direction have been observed without using a DED. Considerable changes in the plasma flow have been obtained using a DED for reducing toroidal and poloidal rotation velocities near the resonant magnetic surface. The change in the plasma rotation velocity was found to couple with the change in the radial electric field.

Copyright (c) 2008 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

plasma rotation, dynamic ergodic divertor, passive spectroscopy, radial electric field, HYBTOK-II

DOI: 10.1585/pfr.3.S1015

Full Text

PDF format (2.8Mbytes)

References

• [1] K. Ida, Phys. Fluids B 4, 2552 (1992).
• [2] Y. Sakamoto et al., Nucl. Fusion 41, 865 (2001).
• [3] S. Takamura, H. Yamada and T. Okuda, Nucl. Fusion 28, 183 (1988).
• [4] M. Kobayashi, H. Kojima, K. Zhai and S. Takamura, Phys. Plasmas 7, 3288 (2000).
• [5] S. Takamura, Y. Kikuchi, Y. Uesugi and M. Kobayashi, Nucl. Fusion 43, 393 (2003).
• [6] M. Kobayashi et al., Nucl. Fusion 40, 181 (2000).
• [7] Y. Kikuchi et al., J. Nucl. Mater. 313-316, 1272 (2003).
• [8] Y. Kikuchi et al., Plasma Phys. Control. Fusion 49, A135 (2007).
• [9] S. Kado and T. Shikama, J. Plasma Fusion Res. 79, 841 (2001).
• [10] K. H. Finken et al., Phys. Rev. Lett. 94, 015003 (2005).
• [11] B. Unterberg et al., J. Nucl. Mater. 363-365, 698 (2007).

This paper may be cited as follows:

Yu HASEBE, Masaaki OKAMOTO, Shin KAJITA, Noriyasu OHNO and Shuichi TAKAMURA, Plasma Fusion Res. 3, S1015 (2008).