Rapid Communications

Full Text / References

First Measurement of Electron Temperature and Density Profiles for Spherical Tokamak Plasmas Sustained by Lower Hybrid Waves

Hiro TOGASHI, Akira EJIRI, Hiroto HOMMA, Takahiro SHINYA, Yuichi TAKASE, Kazuya TOIDA, Naoto TSUJII, Takashi YAMAGUCHI, Yusuke YOSHIDA, Makoto HASEGAWA¹⁾, Yoshihiko NAGASHIMA¹⁾, Hirokazu FURUI, Kenta NAKAMURA, Wataru TAKAHASHI, Toshihiro TAKEUCHI, Masateru SONEHARA, Satoru YAJIMA and Hibiki YAMAZAKI

The University of Tokyo, Kashiwa 277-8561, Japan

1)

Kyushu University, Kasuga 816-8580, Japan

(Received 29 June 2015 / Accepted 1 September 2015 / Published 28 December 2015)

Abstract

In this research, the profiles of electron temperature T_e and density n_e for a spherical tokamak with the plasma current sustained by lower hybrid waves alone have been measured for the first time using Thomson scattering diagnostics in the TST-2 spherical tokamak device. The T_e profile was hollow and the n_e profile was like bell-shaped. T_e and n_e near the plasma center were 6 eV and 6 × 10¹⁷ m⁻³, respectively, leading to a pressure of 0.6 Pa. On the other hand, whole pressure at the plasma center calculated using an equilibrium reconstruction code EFIT was around 20 Pa. Therefore, it is suggested that fast electrons play an important role in the plasma equilibrium.

Copyright (c) 2015 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

TST-2, spherical tokamak, Thomson scattering, lower hybrid wave, current drive

DOI: 10.1585/pfr.10.1202082

Full Text

PDF format (398Kbytes)

References

• [1] H. Meyer et al., Nucl. Fusion 53, 104008 (2013).
• [2] T. Maekawa et al., Nucl. Fusion 45, 1439 (2005).
• [3] K. Hanada et al., Plasma Fusion Res. 5, S1007 (2010).
• [4] A. Ejiri et al., Nucl. Fusion 46, 709 (2006).
• [5] T. Shinya et al., Nucl. Fusion 55, 073003 (2015).
• [6] T. Wakatsuki et al., AIP Conf. Proc. 1580, 422 (2014).
• [7] V.V. D'yachenko et al., Plasma Phys. Rep. 39, 219 (2013).
• [8] T. Yamaguchi et al., Plasma Fusion Res. 8, 1302001 (2013).
• [9] M. Yu. Kantor et al., Plasma Phys. Control. Fusion 51, 055002 (2009).
• [10] H. Togashi et al., Rev. Sci. Instrum. 85, 056103 (2014).
• [11] A. Ejiri et al., Plasma Fusion Res. 5, S2082 (2010).
• [12] S. Tsuda et al., Plasma Fusion Res. 10, 1202064 (2015).

This paper may be cited as follows:

Hiro TOGASHI, Akira EJIRI, Hiroto HOMMA, Takahiro SHINYA, Yuichi TAKASE, Kazuya TOIDA, Naoto TSUJII, Takashi YAMAGUCHI, Yusuke YOSHIDA, Makoto HASEGAWA, Yoshihiko NAGASHIMA, Hirokazu FURUI, Kenta NAKAMURA, Wataru TAKAHASHI, Toshihiro TAKEUCHI, Masateru SONEHARA, Satoru YAJIMA and Hibiki YAMAZAKI, Plasma Fusion Res. 10, 1202082 (2015).