  We investigate electron acceleration resulting from 3D magnetic reconnection
between an emerging, twisted magnetic flux rope and a pre-existing weak, open
magnetic field. We first follow the rise of an unstable, twisted flux tube with
a resistive MHD simulation where the numerical resolution is enhanced by using
fixed mesh refinement. As in previous MHD investigations of similar situations,
the rise of the flux tube into the pre-existing inclined coronal magnetic field
results in the formation of a solar coronal jet. A snapshot of the MHD model is
then used as an initial and boundary condition for a particle-in-cell
simulation, using up to half a billion cells and over 20 billion charged
particles. Particle acceleration occurs mainly in the reconnection current
sheet, with accelerated electrons displaying a power law in the energy
probability distribution with an index of around -1.5. The main acceleration
mechanism is a systematic electric field, striving to maintaining the electric
current in the current sheet against losses caused by electrons not being able
to stay in the current sheet for more than a few seconds at a time.
