Fourier space intermittency of the small-scale turbulent dynamo
UNSPECIFIED. (2003) Fourier space intermittency of the small-scale turbulent dynamo. PHYSICAL REVIEW E, 68 (2 Part 2). -. ISSN 1063-651XFull text not available from this repository.
Official URL: http://dx.doi.org/10.1103/PhysRevE.68.026311
The small-scale turbulent dynamo in the high Prandtl number regime is described in terms of the one-point Fourier space correlators. The second-order correlator of this kind is the energy spectrum and it has been previously studied in detail. We examine the higher order k-space correlators, which contain important information about the phases of the magnetic wave packets and about the dominant structures of the magnetic turbulence which cause intermittency. In particular, the fourth-order correlators contain information about the mean-square phase difference between any two components of the magnetic field in a plane transverse to the wave vector. This can be viewed as a measure of the magnetic field's polarization. Examining this quantity, the magnetic field is shown to become plane polarized in the Kazantsev-Kraichnan model at large times, corresponding to a strong deviation from Gaussianity. We derive a closed equation for the generating function of the Fourier correlators and find the large-time asymptotic solutions of these correlators at all orders. The time scaling of these solutions implies that the magnetic field has log-normal statistics, whereas the wave number scaling indicates that the field is dominated by intermittent fluctuations at high k.
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics|
|Journal or Publication Title:||PHYSICAL REVIEW E|
|Publisher:||AMERICAN PHYSICAL SOC|
|Number:||2 Part 2|
|Number of Pages:||10|
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