It is proposed to make a numerical study, both classically and quantum mechanically, of the stability of distorted Coulomb orbits under the influence of stochastic perturbations. The primary goal of the investigation is the study of the atomic dynamics under the influence of strong noise. The method we will use is the numerical Monte-Carlo solution of a classical Langevin equation and the solution of a quantum master equation for the reduced atomic density matrix. The comparison between the classical and the quantum treatment should provide novel information on the degree of suppression of indeterministic (stochastic) diffusion due to discreteness effects of quantum states. Applications will focus on the dynamical evolution of excited states of fast atomic particles penetrating solids under the combined influence of stochastic collision processes and dynamical screening in the many-body target.
