论文标题
低电阻率等离子体的磁场演化和重新连接
Magnetic field evolution and reconnection in low resistivity plasmas
论文作者
论文摘要
磁场演化的三个方面（拓扑，能量和螺旋性）的数学和物理学非常简单明了。当电阻率$η$与施加的进化相比，$ A/V $，时间尺度，这意味着$ r_m \equivμ_0VA/η>> 1 $，磁场线混沌在三维系统中占主导地位。混乱在能量耗散中没有直接作用。大型电流密度，$j_η\ equiv vb/η$，能量耗散的时间与拓扑演变相当。然而，混乱和alfvén波阻尼解释了为什么两个时间尺度往往比进化时尺$ a/v $要长的数量级。当边界流具有涡度时，将磁性螺旋性注入到场线管中。混乱会传播但不能破坏磁性螺旋。当$ r_m >> 1 $时，电阻率对螺旋积累的影响可忽略不计。螺旋度在田间线管中积聚，直到管爆发并远离原始位置。
The mathematics and physics of each of the three aspects of magnetic field evolution -- topology, energy, and helicity -- is remarkably simple and clear. When the resistivity $η$ is small compared to an imposed evolution, $a/v$, timescale, which means $R_m\equivμ_0va/η>>1$, magnetic field line chaos dominates the evolution of field-line topology in three-dimensional systems. Chaos has no direct role in the dissipation of energy. A large current density, $j_η\equiv vB/η$, is required for energy dissipation to be on a comparable time scale to the topological evolution. Nevertheless, chaos plus Alfvén wave damping explain why both timescales tend to be approximately an order of magnitude longer than the evolution timescale $a/v$. Magnetic helicity is injected onto tubes of field lines when boundary flows have vorticity. Chaos can spread but not destroy magnetic helicity. Resistivity has a negligible effect on helicity accumulation when $R_m>>1$. Helicity accumulates within a tube of field lines until the tube erupts and moves far from its original location.
