Journal article · Preprint article
Anomalous diffusion, clustering, and pinch of impurities in plasma edge turbulence
The turbulent transport of impurity particles in plasma edge turbulence is investigated. The impurities are modeled as a passive fluid advected by the electric and polarization drifts, while the ambient plasma turbulence is modeled using the two-dimensional Hasegawa-Wakatani paradigm for resistive drift-wave turbulence.
The features of the turbulent transport of impurities are investigated by numerical simulations using a novel code that applies semi-Lagrangian pseudospectral schemes. The diffusive character of the turbulent transport of ideal impurities is demonstrated by relative-diffusion analysis of the evolution of impurity puffs.
Additional effects appear for inertial impurities as a consequence of compressibility. First, the density of inertial impurities is found to correlate with the vorticity of the electric drift velocity, that is, impurities cluster in vortices of a precise orientation determined by the charge of the impurity particles.
Second, a radial pinch scaling linearly with the mass-charge ratio of the impurities is discovered. Theoretical explanation for these observations is obtained by analysis of the model equations. (C) 2005 American Institute of Physics.
Language: | English |
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Publisher: | American Institute of Physics |
Year: | 2005 |
ISSN: | 10897674 and 1070664x |
Types: | Journal article and Preprint article |
DOI: | 10.1063/1.1933779 |
ORCIDs: | Naulin, V. and Juul Rasmussen, J. |