  Simulation of the magnetic relaxation in a model of hard superconductor
reveals a new time scale below the irreversibility temperature. The relaxation
in this new time scale, which appears in an intermediate time window, is a
power law and is related to self organization of the magnetic flux around the
critical current density J_c during the relaxation. Emergence of a new time
scale which along with the time scale for long time relaxation due to thermally
activated process dynamically identifies the irreversibility temperature.
