MULTIFRACTAL AND MONOFRACTAL SCALING IN A LABORATORY MAGNETOHYDRODYNAMIC TURBULENCE EXPERIMENT

Journal Article · Sun Sep 20 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/811/1/61· OSTI ID:22525405

Schaffner, D. A.

Both multifractal and monofractal scaling of structure function exponents are observed in the turbulent magnetic fluctuations of the Swarthmore Spheromak Experiment plasma. Structure function and probability distribution function (PDF) analysis exhibits multifractal scaling exponents in low frequency, inertial range fluctuations of the turbulence but monofractal scaling in higher frequency, dissipation range fluctuations. The transition from multifractal to monofractal scaling occurs rapidly suggesting a dissipation mechanism that is insensitive to turbulent structure scale size. Structure functions and PDFs are presented for both temporal and spatial measurements. Variations in the magnetic helicity in the plasma are also shown to modify multifractal scaling characteristics of the inertial range, but do not affect the monofractal scaling of the dissipation range.

• OSTI ID: 22525405
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 811; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
79 ASTRONOMY AND ASTROPHYSICS
DISTRIBUTION FUNCTIONS
FLUCTUATIONS
HELICITY
MAGNETOHYDRODYNAMICS
PLASMA
PROBABILITY
SPHEROMAK DEVICES
STRUCTURE FUNCTIONS
TURBULENCE