2010/01/11 by Andrei N. Simakov, Simakov, Andrei N., L. Chacón +3
Physics and Astronomy · #FOS: Physical sciences #Plasma Physics (physics.plasm-ph) #Space Physics (physics.space-ph) #physics.plasm-ph #physics.space-ph
paper · pdf · doi:10.48550/arxiv.1001.1708
arxiv created 2010/01/11 · arxiv updated 2010/01/14
Analytical theory of fast magnetic reconnection with a large guide field is presented for the first time. We confirm that two distinct reconnection regimes are possible depending on whether the diffusion region thickness δ is larger or smaller than the sound gyroradius ρs. The reconnection is slow or Sweet-Parker-like for δ\gtrsim ρs, and fast otherwise. In the fast regime, however, we find that ion viscosity μ plays a critical role. In particular, for δ< ρs the diffusion region thickness is proportional to Ha-1 with Ha ∝ 1/√(ημ) the Hartmann number, and the reconnection rate is proportional to Pr-1/2 with Pr = μ/η the Prandtl number and η the resistivity. If the perpendicular ion viscosity is employed for μ the reconnection rate becomes independent of both plasma β and collision frequencies and therefore potentially fast.