Spectral stability of Alfvén filament configurations

The two-fluid plasma equations that describe nonlinear Alfvén perturbations have singular solutions in the form of current–vortex filaments. These filaments are analogous to point vortices in ideal hydrodynamics and geostrophic fluids. In this work the spectral (linear) stability of current–vortex filament configurations is analyzed and compared with the results obtained for point vortices in ideal hydrodynamics and the Charney-Hasegawa-Mima equation. We consider single rows, double rows—von Kármán streets—and single and double rings of vortices. In all cases the stability picture for the current–vortex filaments is remarkably different from that of the other two models, which can be recovered as limiting cases of the two-fluid Alfvén model. New regions of perturbations against which the system is stable are identified and the dependence on physical parameters is described.