In Figure , the traces of the magnitude of the transverse magnetization, m x (t) + m y (t) (red) and of the m z component of the magnetization are shown. The typical multiple maser pattern is recovered, and is understood to be due to the presence of two antagonist processes, namely, the radiation feedback that rotates the magnetization vector towards its equilibrium direction, and the (negative) polarization process that builds up the z component of the magnetization towards its stationary state m st 0 . As shown by our experiments, one of the ingredients involved in the dynamics is the presence of a strong enough dipolar field in the sample to affect the evolution of the magnetization. Therefore, we next investigated these through a ensemble of simulations. In our numerical model, the dynamics can be studied by varying its strength through the (uniform) spin density m o assigned to each moment on the lattice, the control parameter for this purpose.