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Drift Wave (drift + wave)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Disparate Scale Nonlinear Interactions in Edge Turbulence

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 1-3 2008
M. Yagi
Abstract In this topical review, we explain the recent achievement in the study of nonlinear interactions, putting an emphasis on the relevance to edge turbulence. First, we start from the survey of the essence in the nonlinear theory of drift wave -zonal flows systems, and visit the experimental observations of the nonlinear interactions of tokamak edge turbulence. Secondly, the universality of intermittent convective transport in the SOL of different magnetic devices are shown. Then, we discuss evolution of collisional drift wave instability in the linear plasma configuration, which is bounded by end plates having analogy to SOL plasmas. By introducing the Numerical Linear Device, the intermittent evolution of large-amplitude instabilities, generation mechanism of the poloidal flow and other nonlinear process are examined. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Doppler spectral line shapes in low frequency turbulent plasmas

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 1-3 2004
Y. Marandet
Abstract In this paper we investigate the influence of low frequency, i.e. drift wave like turbulence on the spectral line shapes in magnetized plasmas. The measured spectrum, which is obtained through both spatial and time averaging processes, is shown to contain information on turbulence. Using a statistical description of the turbulent fluctuations, we investigate the effects of density, fluid velocity and temperature fluctuations on the Doppler profile of a spectral line. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

On the origin of the drifting subpulses in radio pulsars

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2005
G. Gogoberidze
ABSTRACT We present a model for the main observational characteristics of the radio emission of pulsars with well-organized drifting subpulses. We propose that drifting subpulses result from the modulation of the radio emission mechanism due to long-wavelength drift waves in the magnetosphere. The drift waves are generated at shorter wavelengths, and their non-linear evolution favours accumulation in a specific azimuthal eigenmode with an integral number, m, of nodes encircling the magnetic pole. The electric field of the drift waves is along the magnetic field lines, and this modulates the distribution for particles and hence the radio emission mechanism. The ratio of the frequency of the eigenmode to the rotation frequency of the star is insensitive to the magnetic field strength and the period of rotation, and is of order unity. The period, P3, of the drifting subpulses is attributed to the mismatch between this frequency and the nearest harmonic of the rotation frequency of the star. [source]