  We study the dynamical transport in weakly coupled superlattices in the
presence of intense radiation in the THz regime. We derive a general model for
the time dependent tunneling current within the Keldysh
nonequilibrium-Green-function formalism. For the particular situation in which
fast scattering procceses drive the system to local equilibrium in the wells
drastic changes are found in the current vs. voltage curves.
