Relativistic electron production during guide field magnetic reconnection

摘要

The production of relativistic electrons during guide field magnetic reconnection is investigated with two-dimensional particle-in-cell simulations. The acceleration mechanism is found to consist of two important elements. The parallel electric field that exists in the low-density cavities along two of the separatrices leads to the production of a cold electron beam. This beam is funneled into the near vicinity (of the order of a few ion inertia lengths) of the X line where the electrons are further accelerated by the parallel electric field to form the relativistic portion of the electron spectrum. This combined process is more efficient than for undriven magnetic reconnection without a guide field and produces a harder spectrum. Secondary islands which can appear as transient structures during the guide field reconnection process do not appear to play an important role in the production of the relativistic electrons.