Chaotic dynamics in classical nuclear billiards

We consider several noninteracting nucleons moving in a 2D Woods-Saxon type potential well and hitting the vibrating surface. The Hamiltonian has a coupling term between the particle motion and the collective coordinate which generates a self-consistent dynamics. The numerical simulation is based on the solutions of the Hamilton equations which was solved using an algorithm of Runge-Kutta type (order 4-5) having an optimized step size, taking into account that the absolute error for each variable is less than 10(-6). Total energy is conserved with high accuracy, i.e., approx. 10(-6) in absolute value. We analyze the chaotic behavior of the nonlinear dynamics system using phase-space maps, autocorrelation functions, power spectra, Lyapunov exponents and Kolmogorov-Sinai entropies. A qualitative and quantitative picture of the achievement of soft chaos is shown for a comparative study between the adiabatic and the resonance stage of nuclear interaction. We consider that the onset of chaos would be linked to the resonance stage of interaction. This assumption is argued in [1]. (C) 2010 Elsevier B.V. All rights reserved.