Fast dynamic reconnection at X-type neutral points

Abstract

view Abstract Citations (57) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Fast Dynamic Reconnection at X-Type Neutral Points Craig, I. J. ; Watson, P. G. Abstract The time evolution of disturbed X-type neutral points is considered. An analytic treatment is given for the case of small disturbances of the equilibrium field in the absence of gas pressure. This problem admits well-defined azimuthal modes which allow a formally exact determination of the magnetic annihilation rate. Reconnection can only occur in the case of purely radial (m = 0) disturbances. The linear theory supports the notion of an initial implosive stage which rapidly releases the bulk of the energy associated with reconnective field disturbances. In the nonlinear problem, although fast reconnection is maintained for low-amplitude disturbances in noncylindrical geometries, finite gas pressure can stall the reconnection if sufficiently large. This effect may not be critical in more complex X-point geometries. More seriously, for finite-amplitude disturbances the cylindrical current structure close to the neutral point is distorted into a quasi-one-dimensional current sheet whose thickness is limited by resistive diffusion. In this case fast reconnection is consistent with a flux pileup solution in which the bulk of the energy is released as heat rather than as the kinetic energy of mass motion. Publication: The Astrophysical Journal Pub Date: July 1992 DOI: 10.1086/171512 Bibcode: 1992ApJ...393..385C Keywords: Magnetic Field Reconnection; Magnetohydrodynamics; Solar Corona; Solar Flares; Linear Equations; Scaling Laws; Solar Physics; MAGNETOHYDRODYNAMICS: MHD full text sources ADS |