Generation of Suprathermal Electrons during Magnetic Reconnection

In a highly magnetized plasma, the motion of electrons is strongly linked to the dynamics of the magnetic field lines. For this reason, the electron behaviour becomes particularly int eresting in regions where significant changes of the magnet ic t opology occur, as in the case of magnetic reconnection. Energetic electrons peaked around the X - line are seen during magnetic reconnection events, such as sawtooth crashes and disruptions, in tokamak experiments (1) (2). Collisionless reconnection can account for fast relaxations in laboratory fusion plasmas, where the temperature is so high that the relaxation time can be shorter than the electron -ion collisio n t ime and therefore resistivity can be neglected. The aim of the present work is to investiga te the electron dynamics in the presence of the electric and magnetic fields that are characteristic of collisionless magnetic reconnection in a strongly magnetized plasma. We consider a two -fluid model describing the reconnection process, which includes t he effects of the electron parallel compressibility and of the electron inertia in Ohm's law and assumes that the electron temperature is constant during all stages of the process in the reconnection domain. This model leads to a system o f t wo di fferential equations expressing the evolution in time of the generalized