Collisionless Magnetic Reconnection in Thin Current Sheets: Results of 
Full Particle Simulations

M. Scholer (Max-Planck-Institut fuer extraterrestrische Physik)

Three-dimensional  particle-in-cell simulations of
collisionless magnetic reconnection  will be presented. The initial
equilibrium is a double Harris-sheet equilibrium with a width of the order
of one ion inertial length. No magnetic seed island is imposed initially,
and no flow conditionsare imposed. In the exactly antiparallel case the
inductive field of the waves excited by the lower hybrid drift instability
leads to rapid acceleration of the electrons in the center of the
current sheet and  to  current sheet thinning.  In the thin current sheet
rapidly reconnection sets in which self-organizes into a two-dimensional
structure with a single X line. In most space and astrophysical settings 
the
magnetic field is not exactly anti-parallel but a guide field in the
current direction exists. We will present simulations to demonstrate how
such a guide field modifies the quick reconnection onset. We will also
present recent two- and three-dimensional simulation results of 
reconnection
in thin current sheets in an electron-positron plasma. In particular
we will discuss how  particle acceleration will be modified in a
three-dimensional configuration due to the finite extent of the 
acceleration
region.