Energy Transfer and Electron Energization in Collisionless Magnetic Reconnection for Different Guide-Field Intensities

Electron dynamics and energization are a key component of magnetic field dissipation in collisionless reconnection. In 2D reconnection, the main mechanism that limits the current density and provides an effective dissipation is most probably the electron pressure tensor term, that breaks the frozen-in condition at the x-point. The electron-meandering-orbit scale controls the width of the electron dissipation region, where electron temperature is seen to increase both in recent MMS observations and laboratory experiments (MRX). By means of 2D, full-particle simulations in an open system we investigate how energy conversion and particle energization depend on guide field intensity. We study energy transfer from the electromagnetic field to the plasma, and the threshold guide field separating dominant parallel rather than perpendicular energy transfer. We calculate the energy partition between fields and kinetic and thermal energy of different species, from the electron scales to ion scales, showing there is no significant variation for different guide field configurations. Finally we study electron distribution functions and self consistently evolved particles orbits for high guide field configuration, investigating possible mechanisms for electron perpendicular heating.