The temporal dynamics of a storage-ring Free Electron Laser is here
investigated with particular attention to the case in which an external
modulation is applied to the laser-electron beam detuning. The system is shown
to produce bifurcations, multi-furcations as well as chaotic regimes. The
peculiarities of this phenomenon with respect to the analogous behavior
displayed by conventional laser sources are pointed out. Theoretical results,
obtained by means of a phenomenological model reproducing the evolution of the
main statistical parameters of the system, are shown to be in a good agreement
with experiments carried out on the Super-ACO Free Electron Laser.Comment: submitted to Europ Phys. Journ.
