No abstract

A simple model of forced magnetic reconnection in a force-free magnetic field is considered, which allows the calculation of the magnetic energy release during the current sheet reconnection. The dependence of this energy on characteristics of the magnetic configuration has been studied, and it was found that the released energy becomes very large when the field is near the marginal tearing stability. A persistent plasma heating provided by ongoing external driving and internal reconnection is most efficient when the time-scales of these processes are comparable. Possible implications of the obtained results for the problem of solar coronal heating are briefly discussed.

Adiabatic acceleration of charged particles along magnetic field lines originates from the coupling between the electric drift and longitudinal motion in a nonunidirectional magnetic field. As a result, initially slow particles entering the reconnection site of an X-type magnetic geometry can leave the latter as substantially accelerated jets directed along the magnetic separatrices. The corresponding energy spectrum has a power-law form, with the spectral index depending on the angle between the separatrices.

Abstract. The acceleration of charged particles at a two-dimensional magnetic reconnecfion site is investigated. The magnetic field has an X-type neutral point, while reconnection is driven by a uniform transverse electric field; the effect of including a uniform magnetic field component parallel to the driving electric field and transverse to the plane of the X point is studied. We focus on the adiabatic motion of strongly magnetized particles, a valid assumption everywhere for sufficiently strong parallel magnetic fields but one which excludes a region around the neutral point for weaker fields. The regime of interest is fast driven reconnection, in which the electric drffi is strong. The trajectories of particles and their dependence on the magnitude of the parallel magnetic field component are investigated. Particles can be accelerated along the magnetic field lines both because of the coupling of the perpendicular electric drift with the parallel motion, which occurs in an inhomogeneous magnetic field, and the direct acceleration by the electric field. The energy spectra of particles leaving the reconnection site are also calculated.

If a compact bunch of charged particles or current rings moves in an electromagnetic field, the force on the bunch gets an additional contribution which has a form of interaction between the electric dipole moment of a bunch and a magnetic field. This comes besides the relativistic transformation of the electric and magnetic dipole moments of a moving bunch, and possible combined effects are illustrated with simple examples.