  We study the statistics of multi-photon absorption/emission processes in a
mesoscopic ring threaded by an harmonic time-dependent flux $\Phi(t)$. For this
sake, we demonstrate a useful analogy between the Keldysh quantum kinetic
equation for the electrons distribution function and a Continuous Time Random
Walk in energy space with corrections due to interference effects. Studying the
probability to absorb/emit $n$ quanta $\hbar\omega$ per scattering event, we
explore the crossover between ultra-quantum/low-intensity limit and
quasi-classical/high-intensity regime, and the role of multiphoton processes in
driving it.
