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Title: Drift wave vortices in nonuniform plasmas with sheared magnetic fields

Technical Report ·
DOI:https://doi.org/10.2172/10116185· OSTI ID:10116185

Nonlinear coherent structures governed by the coupled drift wave-ion acoustic mode equations in nonuniform plasmas with sheared magnetic fields are studied analytically and numerically. A solitary vortex equation that includes the effects of density and temperature gradients, and magnetic shear is derived and analyzed. The analytic and numerical studies show that for a plasma in a sheared magnetic field, even without the temperature and drift velocity gradients, solitary vortex solutions are possible; however, these solutions are not exponentially localized due to the presence of a nonstructurally stable perturbative tail that connects to the core of the vortex. The new coherent vortex structures are dipole-like in their symmetry, but are not the modons of Larichev and Reznik. In the presence of a small temperature or drift velocity gradient, the new shear-induced dipole can not survive and will separate into monopoles, like the case of the modon in a sheared drift velocity as studied in Su et al. The solitary solutions are found from the nonlinear eigenvalue problem for the effective potential in a quasi-one-dimensional approximation. The numerical simulations are performed in 2-D with the coupled vorticity and parallel mass flow equations.

Research Organization:
Univ. of Texas, Austin, TX (United States). Institute for Fusion Studies
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FG05-80ET53088
OSTI ID:
10116185
Report Number(s):
DOE/ET/53088-523; IFSR-523; ON: DE92006879
Resource Relation:
Other Information: PBD: Nov 1991
Country of Publication:
United States
Language:
English