  We examine through numerical calculation the collision of counter-propagating
trains of optically spaced electron/positron microbunches in a 1 TeV collider
scenario for a dielectric laser accelerator (DLA). A time-dependent envelope
equation is derived for arbitrary number of bunches in the classical limit,
with inclusion of the radiation reaction force (RRF). Example parameters are
examined based on a constrained luminosity relation that takes into account the
bunch charge for optimal efficiency, material damage limits, and power
constraints. We find that for initially identical counter-propagating Gaussian
bunch trains the periodic temporal structure leads to a peak in luminosity with
number of bunches. For longer bunch trains, the enhancement then decreases
inversely with number of bunches. The corresponding fractional energy loss of
the beam is found to be of order 1.75\%, which is reduced to 0.35\% when the
nonlinear radial dependence of the transverse force is included, with an
average beamstrahlung parameter of 0.075, an important result considering that
beamstrahlung losses are a critical concern for future TeV colliders.
