Nonlinear viscoresistive dynamics of the m=1 tearing instability

Takeda, K., Agullo, O., Benkadda, S., Sen, A., Bian, N.H. and Garbet, X. (2008) Nonlinear viscoresistive dynamics of the m=1 tearing instability. Physics of Plasmas, 15(2), 022502. (doi: 10.1063/1.2839351)

Full text not currently available from Enlighten.

Abstract

A numerical investigation of the viscoresistive evolution of the m=1tearing instability is presented. Its linear growth rate is found to have various power law scalings in different viscoresistive regimes, in agreement with the theoretical results of Porcelli [Phys. Fluids30, 1734 (1987)]. Our principal focus is on the nonlinear behavior of this instability at a high value of the stability parameter Δ′ and for different values of the Prandtl number Pm. It is found that, depending on the Prandtl regime, and in association with a poloidal oscillation of the magnetic structure, a quadrupolar flow can be generated and/or destroyed outside the current sheet. The reconnection process appears to be influenced by the generation/inhibition dynamics of this external quadrupolar flow. At large enough times, this nonlinear quadrupolar flow can be partially advected in the poloidal direction at the Alfvén velocity. However at high Pm values, such an advection is inhibited by viscosity and, as a consequence, the latter contributes to the reduction of the amplitude of the poloidal oscillations.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Bian, Dr Nicolas Horace
Authors: Takeda, K., Agullo, O., Benkadda, S., Sen, A., Bian, N.H., and Garbet, X.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Physics of Plasmas
Publisher:American Institute of Physics
ISSN:1070-664X
ISSN (Online):1089-7674

University Staff: Request a correction | Enlighten Editors: Update this record