  We propose a theory based on simple physical arguments that describes a non
equilibrium steady-state by a temperature-like parameter (an "effective
temperature"). We show how one can predict the effective temperature as a
function of the temperature of the environment for a specific case of
non-equilibrium behavior: radiation amorphization. The main idea that we
present is that the amorphization process is inherently connected to the
dynamical arrest that a liquid undergoes when it transforms into a glass. We
suggest that similar arguments may hold also for the effective temperature
under plastic deformation.
