[Table of Contents]

Plasma and Fusion Research

Volume 5, 022 (2010)

Rapid Communications

Observation of Edge Reynolds Stress Increase Preceding an L-H Transition in Compact Helical System
Yoshihiko NAGASHIMA, Kenichi NAGAOKA1), Kimitaka ITOH1), Akihide FUJISAWA2), Mitsutaka ISOBE1), Tsuyoshi AKIYAMA1), Chihiro SUZUKI1), Shin NISHIMURA1), Yasuo YOSHIMURA1), Keisuke MATSUOKA1), Shoichi OKAMURA1), Yuichi TAKASE, Akira EJIRI, Sanae -I. ITOH2), Masatoshi YAGI2) and CHS Group1)
Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 509-5292, Japan
National Institute for Fusion Science, Toki 509-5292, Japan
Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580, Japan
(Received 28 February 2010 / Accepted 6 April 2010 / Published 14 June 2010)


An increase in turbulent Reynolds stress preceding an L-H transition in the Compact Helical System (CHS) was observed. A positive increase in the Reynolds stress is associated with a negative jump in the floating potential. The relationship of signs is consistent with the momentum balance equation. Therefore, this observation supports the hypothesis that the Reynolds stress plays an important role in triggering the L-H transition in CHS plasmas.


L-H transition, Reynolds stress

DOI: 10.1585/pfr.5.022


  • [1] F. Wagner et al., Phys. Rev. Lett. 49, 1408 (1982).
  • [2] S. Okamura et al., Nucl. Fusion 45, 863 (2005).
  • [3] Y.H. Xu et al., Phys. Rev. Lett. 84, 3867 (2000).
  • [4] K. Nagaoka et al., Phys. Rev. Lett. 100, 065005 (2008).
  • [5] S.P. Hirshman et al., Comput. Phys. Commun. 43, 143 (1986).
  • [6] Y. Nagashima et al., Phys. Plasmas 16, 020706 (2009).
  • [7] S. Nishimura et al., Plasma Fusion Res. 2, 037 (2007).
  • [8] M. Takeuchi et al., Nucl. Fusion 48, 024015 (2008).

This paper may be cited as follows:

Yoshihiko NAGASHIMA, Kenichi NAGAOKA, Kimitaka ITOH, Akihide FUJISAWA, Mitsutaka ISOBE, Tsuyoshi AKIYAMA, Chihiro SUZUKI, Shin NISHIMURA, Yasuo YOSHIMURA, Keisuke MATSUOKA, Shoichi OKAMURA, Yuichi TAKASE, Akira EJIRI, Sanae -I. ITOH, Masatoshi YAGI and CHS Group, Plasma Fusion Res. 5, 022 (2010).