  Reconnection is one of the key processes in astrophysical and laboratory
plasmas: it is the opposite of a dynamo. Looking at energy, a dynamo transforms
kinetic energy in magnetic energy while reconnection takes magnetic energy and
returns is to its kinetic form. Most plasma processes at their core involve
first storing magnetic energy accumulated over time and then releasing it
suddenly. We focus here on this release. A key concept in analysing
reconnection is that of the separatrix, a surface (line in 2D) that separates
the fresh unperturbed plasma embedded in magnetic field lines not yet
reconnected with the hotter exhaust embedded in reconnected field lines. In
kinetic physics, the separatrices become a layer where many key processes
develop. We present here new results relative to the processes at the
separatrices that regulate the plasma flow, the energisation of the species,
the electromagnetic fields and the instabilities developing at the
separatrices.
