  This paper presents two-fluid simulations of forced magnetic reconnection
with finite electron inertia in a collisionless three-dimensional (3D) cube
with periodic boundaries in all three directions. Comparisons are made to
analogous two-dimensional (2D) simulations. Reconnection in this system is
driven by a spatially localized forcing function that is added to the ion
momentum equation inside the computational domain. Consistent with previous
results in similar, but larger forced 2D simulations [B. Sullivan, B. N.
Rogers, and M. A. Shay, Phys. Plasmas 12, 122312 (2005)], for sufficiently
strong forcing the reconnection process is found to become Alfvenic in both 2D
and 3D, i.e., the inflow velocity scales roughly like some fraction of the
Alfven speed based on the upstream reconnecting magnetic field, and the system
takes on a stable configuration with a dissipation region aspect ratio on the
order of 0.15.
