  We analyze on a simple classical billiard system the onset of chaotical
behaviour in different dynamical states. A classical version of the "nuclear
billiard" with a 2D deep Woods-Saxon potential is used. We take into account
the coupling between the single-particle and the collective degrees of freedom
in the presence of dissipation for several vibrational multipolarities. For the
considered oscillation modes an increasing divergence of the nucleonic
trajectories from the adiabatic to the resonance regime was observed. Also, a
peculiar case of intermittency is reached in the vicinity of the resonance, for
the monopole case. We examine the order-to-chaos transition by performing
several types of qualitative analysis including sensitive dependence on the
initial conditions, single-particle phase space maps, fractal dimensions of
Poincare maps and autocorrelation functions.
