Generation of fast charged particles in a superposition of oscillating electric fields with stochastically jumping phases

Resumo

The motion of a nonrelativistic charged particle in an alternating electric field representing a superposition of monochromatic waves with phases described by stochastic jumplike functions of time has been studied. Statistical analysis is performed in the framework of an exactly solvable model, in which the phases are treated as independent random telegraph signals. The mean kinetic energy of the charged particle is calculated. It is shown that there is a manifold of characteristics of stochastically jumping phases (shift amplitudes and mean frequencies) for which the oscillating mean energy grows with the time. For time periods much greater than the characteristic decay time of phase correlations, the mean kinetic energy linearly increases with time (stochastic heating). The growth rate nonmonotonically depends on the parameters of phase jumps, and the maximum increment is proportional to the number of harmonics.