Magnetic Reconnection in Plasmas



Magnetic reconnection is one of the most fascinating subjects in plasma physics. It is basically a process by which the close tie between plasma motions and magnetic fields is broken. This enables plasma to penetrate magnetic boundaries; for instance, to enter into the Earth's magnetosphere from the solar wind. It is also a key process in explosive processes, converting magnetic energy into plasma kinetic and thermal energy, such as solar flares, magnetospheric substorms, as well as current disruptions in laboratory devices.

The concept of magnetic reconnection was first introduced in 1946 by Ronald G. Giovannelli as a suggested mechanism for particle acceleration in solar flares. Consistent with modern definitions of reconnection, he related this process to the presence of an electric field in a region of low-magnetic field strength or parallel to the magnetic field, both of which require the breakdown of the ideal magnetohydrodynamic (MHD) “frozen-in” field concept and enable charged particle acceleration.