Stochastic heating and stochastic outer ionization of an atomic cluster in a laser field

The dynamics of cluster electrons in a laser field is considered in the framework of the nonlinear oscillator model. The point map describing the motion of a cluster electron in the laser field is constructed. The critical value of the laser field, at which a transition to stochastic motion takes place, is determined. As a result of random walk in the energy space, an electron may accumulate an energy sufficient for overcoming the cluster potential barrier and for passing to the continuum. In this case, outer ionization of the cluster takes place. Estimates are obtained for the heating rate and the time of stochastic outer ionization of the cluster.