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Title: Particle simulations of current-driven drift waves in shearless and sheared magnetic fields

Journal Article · · Phys. Fluids; (United States)
DOI:https://doi.org/10.1063/1.865706· OSTI ID:7163604

The nonlinear behavior of the collisionless current-driven drift instability in shearless and sheared magnetic fields is studied by means of particle simulation. Electrostatic models with guiding center electrons and full dynamic ions are used in both two-and-one-half and three dimensions. The electron current (J/sub parallel/), in the direction parallel to the magnetic field but perpendicular to the density gradient in the x direction, is maintained throughout the simulation. Instability thresholds, growth rates, real frequency spectra, and mode structures observed in the simulation are in good agreement with theory. Saturation of the unstable modes occurs by a flattening of the electron distribution function in x-v/sub parallel/ space. The measured potential saturation levels and final distribution functions are consistent with a quasilinear plateau theory for both shearless and sheared magnetic field configurations.

Research Organization:
Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712-1060
OSTI ID:
7163604
Journal Information:
Phys. Fluids; (United States), Vol. 29:12
Country of Publication:
United States
Language:
English