  We present an exact time-dependent solution to the effective D-brane
world-volume theory which describes an inhomogeneous decay of a brane-antibrane
system. We compute the quantum energy flux induced by the particle creation in
this inhomogeneous and time-dependent background. We find that this calculation
is essentially equivalent to that of the moving mirror system. In the initial
stage, the energy flux turns out to be thermal with the temperature given by
the inverse of the distance between the brane and the antibrane. Later it
changes its sign and becomes a negative energy flux. Our result may be relevant
for the (p)reheating process or/and the evolution of cosmic string network
after stringy brane inflation.
