Abstract:
A simple model of the Fermi acceleration of a particle placed between two periodically oscillating walls is considered. The motion of the walls obeys a continuous (but not smooth) law. An exact map of such a system is obtained. The existence of trajectories with an infinitely increasing velocity is shown. The main characteristics of these trajectories are discussed. The results are compared with those obtained in a high-energy approximation. The exact and approximate descriptions are found to differ qualitatively. Specifically, the trajectories with an infinitely increasing velocity are absent in the high-energy approximation.