Continuous transition from fast magnetic reconnection to slow reconnection and change of the reconnection system structure

Abstract

This paper analytically investigates a series of two-dimensional MHD reconnection solutions over a wide variation of magnetic Reynolds number ($R_{em}^{\ast }$). A new series of solutions explains a continuous transition from Petschek-like fast regime to a Sweet-Parker-like slow regime. The inflow region is obtained from a Grad-Shafranov analysis used by Nitta et al. 2002 and the outflow region from a shock-tube approximation used by Nitta 2004, 2006. A single X-point (Petschek-like) solution forms for a sufficiently small $R_{em}^{\ast }$. As $R_{em}^{\ast }$ gradually increases, the solutions shifts to an X-O-X solution with a magnetic island between two X-points. When $R_{em}^{\ast }$ increases further, the island collapses to a new elongated current sheet with Y-points at both ends (Sweet-Parker-like). These reconnection structures expand self-similarly as time proceeds. As $R_{em}^{\ast }$ increases, the reconnection rate and the reducible fraction of the initial magnetic energy of the system decrease as power-law functions of $R_{em}^{\ast }$.

19 pages, 12 figures

References in corpus (4)

• Measurement of the Energy Release Rate and the Reconnection Rate in Solar Flares
• Statistical Study of the Reconnection Rate in Solar Flares Observed with YOHKOH/SXT
• Outflow structure and reconnection rate of the self-similar evolution model of fast magnetic reconnection
• Magnetic Reynolds number dependence of reconnection rate and flow structure of the self-similar evolution model of fast magnetic reconnection

Cited by in corpus (3)

• Spontaneous non-steady magnetic reconnection within the solar environment
• Effects of magnetic shear and thermodynamic asymmetry on spontaneous MHD magnetic reconnection
• Chaos-induced resistivity in different magnetic configurations