Possible signatures of dissipation from time-series analysis techniques using a turbulent laboratory magnetohydrodynamic plasma
Phys. Plasmas 23, 055709 (2016); http://dx.doi.org/10.1063/1.4948275
Abstract: 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 fluctuationenergy similar to that observed in fluid and magnetohydrodynamicturbulence 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.