Quasilinear stochastic electron energy diffusion driven by an intense cyclotron wave in oblique propagation

The dynamics of electrons in a magnetically confined plasma under the action of an intense monochromatic wave is analyzed by means of a relativistic Hamiltonian treatment. Oblique wave propagation with respect to the magnetic field is considered. It is found that in the case of global stochasticity the particle acceleration has a diffusive nature. It is shown that in a proper space the energy diffusion equation is one dimensional. The relevant diffusion coefficient is given by a well defined local quasilinear expression. The theoretical model is validated up to high values of the perturbation parameter by comparison with long time numerical simulations of the electron motion.