Possible signatures of dissipation from time-series analysis techniques using a turbulent laboratory magnetohydrodynamic plasma

Journal Article · Sun May 15 04:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4948275· OSTI ID:22600232

Schaffner, D. A. ^[1]; Brown, M. R.; Rock, A. B. ^[2]

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1. Department of Physics, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010 (United States)
2. Department of Physics and Astronomy, Swarthmore College, Swarthmore, Pennsylvania 19081 (United States)

The frequency spectrum of magnetic fluctuations as measured on the Swarthmore Spheromak Experiment is broadband and exhibits a nearly Kolmogorov 5/3 scaling. It features a steepening region which is indicative of dissipation of magnetic fluctuation energy similar to that observed in fluid and magnetohydrodynamic turbulence systems. Two non-spectrum based time-series analysis techniques are implemented on this data set in order to seek other possible signatures of turbulent dissipation beyond just the steepening of fluctuation spectra. Presented here are results for the flatness, permutation entropy, and statistical complexity, each of which exhibits a particular character at spectral steepening scales which can then be compared to the behavior of the frequency spectrum.

• OSTI ID: 22600232
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 23; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPARATIVE EVALUATIONS
ENTROPY
FLUCTUATIONS
FLUIDS
MAGNETOHYDRODYNAMICS
PLASMA
SPECTRA
SPHEROMAK DEVICES
TIME-SERIES ANALYSIS
TURBULENCE