Rapid Communications

Full Text / References

On the Nonlinear Coupling of the High Wavenumber Fluctuations Exhibiting the Discrete Spectra Observed in PANTA

Yuichi KAWACHI¹⁾, Makoto SASAKI^2,3), Takashi NISHIZAWA^3,4), Yusuke KOSUGA^3,4), Kenichiro TERASAKA⁵⁾, Shigeru INAGAKI⁶⁾, Takuma YAMADA⁷⁾, Naohiro KASUYA^3,4), Chanho MOON^3,4), Yoshihiko NAGASHIMA^3,4), Akihide FUJISAWA^3,4)

1)

Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan

2)

College of Industrial Technology, Nihon University, Narashino 275-8575, Japan

3)

Research Center for Plasma Turbulence, Kyushu University, Fukuoka 816-8580, Japan

4)

Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580, Japan

5)

Department of Computer and Information Sciences, Sojo University, Kumamoto 860-0082, Japan

6)

Institute of Advanced Energy, Kyoto University, Uji 611-0011, Japan

7)

Faculty of Arts and Science, Kyushu University, Motooka, Fukuoka 819-0395, Japan

(Received 23 August 2024 / Accepted 11 September 2024 / Published 10 November 2024)

Abstract

We report on the nonlinear coupling properties of high-wavenumber fluctuation, which exhibits discrete frequency spectra with a frequency span comparable to the ion cyclotron frequency observed in PANTA. Bicoherence analysis is used to investigate this nonlinear coupling. The results indicate a finite coupling between individual discrete peaks but no coupling between the ion cyclotron frequency components of these discrete peaks. This suggests that the observed turbulence with a discrete spectrum is destabilized linearly rather than through nonlinear coupling.

Copyright (c) 2024 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

high wavenumber turbulence, ion cyclotron ranges of frequency fluctuations, nonlinear interaction

DOI: 10.1585/pfr.1201031

Full Text

PDF format (1.4Mbytes)

References

• [1] W. Dorland et al., Phys. Rev. Lett. 85, 5579 (2000).
• [2] V.V. Mikhailenko et al., Phys. Rev. Lett. 31, 032307 (2024).
• [3] R.O. Dendy et al., Phys. Rev. Lett. 130, 105102 (2023).
• [4] D.S. Thompson et al., Phys. Plasmas 24, 063517 (2017).
• [5] Y. Kawachi et al., Sci. Rep. 12, 19799 (2024).
• [6] Y. Kawachi et al., Plasma Phys. Control. Fusion 65, 115001 (2023).
• [7] Y. Kawachi et al., Phys. Plasmas 31, 044502 (2024).
• [8] S. Inagaki et al., Sci. Rep. 6, 22189 (2016).
• [9] T. Yamada et al., Nat. Phys. 4, 721 (2008).
• [10] Ira B. Bernstein, Phys. Rev. 109, 10 (1958).
• [11] Y. Kawachi et al., Phys. Plasmas 28, 112302 (2021).
• [12] W.E. Amatucci et al., Phys. Rev. Lett. 77, 1978 (1996).