[Table of Contents]

Plasma and Fusion Research

Volume 5, S2047 (2010)

Regular Articles

Bispectral Analysis of Density and Potential Fluctuations in a High Neutral Density Cylindrical Plasma
Tatsuya KOBAYASHI, Shigeru INAGAKI1), Hiroyuki ARAKAWA, Kunihiro KAMATAKI, Yoshihiko NAGASHIMA2), Takuma YAMADA2), Satoru SUGITA, Masatoshi YAGI1), Naohiro KASUYA3), Akihide FUJISAWA1), Sanae -I. ITOH1) and Kimitaka ITOH3)
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka 816-8580, Japan
1)
Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580, Japan
2)
Graduate School of Frontier Sciences, The University of Tokyo, Tokyo 277-8561, Japan
3)
National Institute for Fusion Science, Toki 509-5292, Japan
(Received 7 December 2009 / Accepted 16 March 2010 / Published 10 December 2010)

Abstract

The structure of fluctuations in the Large Mirror Device-Upgrade (LMD-U) depends on the neutral density. In this study, we focus on the high neutral density plasma in which the potential and density fluctuation waveforms are nontrigonometric functions similar to sawtooth waves, and peaks in the power spectrum lie along a straight line when plotted as frequency versus wavenumber. Two-dimentional auto and cross bispectral analyses of Iis and/or Vf, which consider both the matching conditions for both the azimuthal wavenumber and the frequency, have been performed; significant couplings are observed at particular peak frequencies. Similarities and differences between the auto and cross bicoherence of Iis and/or Vf are discussed.

Keywords

linear plasma, drift wave, turbulence, bispectral analysis, nonlinear coupling

DOI: 10.1585/pfr.5.S2047

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References

  • [1] P. H. Diamond et al., Plasma Phys. Control. Fusion 47, R35 (2005).
  • [2] K. Itoh et al., Phys. Plasmas 13, 055502 (2007).
  • [3] T. Klinger et al., Phys. Rev. Lett. 79, 3913 (1997).
  • [4] M. Kono et al., Phys. Rev. Lett. 84, 4369 (2000).
  • [5] C. Schröder et al., Phys. Rev. Lett. 86, 5711 (2001).
  • [6] G. R. Tynan et al., Plasma Phys. Control. Fusion 48, S51 (2006).
  • [7] T. Kaneko et al., Phys. Rev. Lett. 90, 125001 (2003).
  • [8] V. Sokolov et al., Phys. Rev. Lett. 92, 165002 (2004).
  • [9] Y. Nagashima et al., Plasma Phys. Control. Fusion 48, S1 (2006).
  • [10] Y. Nagashima et al., Phys. Rev. Lett. 95, 9, 90905 (1-8) (2005).
  • [11] Y. Nagashima et al., Plasma Phys. Control. Fusion 49, 1611 (2007).
  • [12] T. Yamada et al., Plasma Fusion Res. 3, S1021 (2008).
  • [13] T. Yamada et al., Nature Phys 4, 721 (2008).
  • [14] D. Gresillon et al., Phys. Fluids 31, 1904 (1988).
  • [15] H. Arakawa et al., Plasma Phys. Control. Fusion 51, 85001 (2009).

This paper may be cited as follows:

Tatsuya KOBAYASHI, Shigeru INAGAKI, Hiroyuki ARAKAWA, Kunihiro KAMATAKI, Yoshihiko NAGASHIMA, Takuma YAMADA, Satoru SUGITA, Masatoshi YAGI, Naohiro KASUYA, Akihide FUJISAWA, Sanae -I. ITOH and Kimitaka ITOH, Plasma Fusion Res. 5, S2047 (2010).