processes with the chaotical behaviour of nuclear systems .

A few options in choosing the collective oscillation frequencies have come into focus in the past years, in connection with the onset of chaoticity for “nuclear billiards”. First of all, the issue of dissipation into thermal motion of the adiabatic collective vibrational energy of the potential well was treated for several multipolarities by Burgio, Baldo *et al.* . On the other hand, when trying to associate different vibration frequencies to various nuclear processes, the path to chaos was found to be changed with the order of multipole [@felea-01; @felea-02; @bordeianu-08a; @bordeianu-08b; @bordeianu-08c; @felea-09a].

This paper was intended to bring a quantitative argumentation, based on a systematic study of the configuration and kinetic energy spaces, power spectra, informational entropies, and largest Lyapunov exponents. The study was done in completion of a few qualitative types of analysis previously presented [@felea-09a]: sensitive dependence on the initial conditions, single-particle phase space maps, fractal dimensions of Poincare maps, and autocorrelation functions.

In short, we remind that, by studying the nucleonic dynamics in a Woods-Saxon potential, one can find an increase of the chaotical degree of the system behaviour as raising the frequency of 2D wall oscillation.

