Magnetic field evolution and reconnection in low resistivity plasmas

The mathematics and physics of each the three aspects magnetic field evolution—topology, energy, helicity—are remarkably simple clear. When resistivity η is small compared to an imposed evolution, a/v, timescale, which means Rm≡μ0va/η≫1, field-line chaos dominates evolution topology in three-dimensional systems. Chaos has no direct role dissipation energy. A large current density, jη≡vB/η, required for energy be on a comparable timescale topological evolution. Nevertheless, plus Alfvén wave damping explain why both timescales tend approximately order magnitude longer than a/v. Magnetic helicity injected onto tubes lines when boundary flows have vorticity. can spread but not destroy helicity. Resistivity negligible effect accumulation Rm≫1. Helicity accumulates within tube until erupts moves far from its original location.