2015/02/28 by Luca Comisso, L. Comisso, D. Grasso +3 · 3 citations
Physics and Astronomy · #Amplitude #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Magnetic reconnection #Magnetohydrodynamic drive #Magnetohydrodynamics #Perturbation (astronomy) #Plasma #Plasmoid #Solar and Space Plasma Dynamics #astro-ph.HE #astro-ph.SR #physics.plasm-ph #physics.space-ph
paper · pdf · doi:10.1063/1.4918331
published as Phys. Plasmas 22, 042109 (2015) · Accepted for publication in Physics of Plasmas
openalex publication_date 2015/04/01 · arxiv created 2015/04/15 · arxiv updated 2015/04/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A fundamental problem of forced magnetic reconnection has been solved taking into account the plasmoid instability of thin reconnecting current sheets. In this problem, the reconnection is driven by a small amplitude boundary perturbation in a tearing-stable slab plasma equilibrium. It is shown that the evolution of the magnetic reconnection process depends on the external source perturbation and the microscopic plasma parameters. Small perturbations lead to a slow nonlinear Rutherford evolution, whereas larger perturbations can lead to either a stable Sweet-Parker-like phase or a plasmoid phase. An expression for the threshold perturbation amplitude required to trigger the plasmoid phase is derived, as well as an analytical expression for the reconnection rate in the plasmoid-dominated regime. Visco-resistive magnetohydrodynamic simulations complement the analytical calculations. The plasmoid formation plays a crucial role in allowing fast reconnection in a magnetohydrodynamical plasma, and the presented results suggest that it may occur and have profound consequences even if the plasma is tearing-stable.