Scientific Reports (Dec 2022)

Spatiotemporal dynamics of high-wavenumber turbulence in a basic laboratory plasma

  • Yuichi Kawachi,
  • Makoto Sasaki,
  • Yusuke Kosuga,
  • Kenichiro Terasaka,
  • Takashi Nishizawa,
  • Takuma Yamada,
  • Naohiro Kasuya,
  • Chanho Moon,
  • Shigeru Inagaki

DOI
https://doi.org/10.1038/s41598-022-23559-1
Journal volume & issue
Vol. 12, no. 1
pp. 1 – 9

Abstract

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Abstract High-spatial resolution observation of high-wavenumber broadband turbulence is achieved by controlling the magnetic field to be relatively low and measuring with a azimuthally arranged multi-channel Langmuir array in a basic laboratory plasma. The observed turbulence consists of narrowband low-frequency fluctuations and broadband high-frequency turbulent fluctuations. The low-frequency fluctuations have a frequency of about 0.7 times the ion cyclotron frequency and a spatial scale of 1/10 of the ion inertial scale. In comparison, high-frequency fluctuations have a higher frequency than the ion cyclotron frequency and spatial scales of 1/10–1/40 of the ion inertial scale. Two-dimensional correlation analysis evaluates the spatial and temporal correlation lengths and reveals that the high-wavenumber broadband fluctuations have turbulent characteristics. The measurements give us further understanding of small scale turbulence in space and fusion plasmas.