Suppression of the pulsed regimes appearing in free-electron lasers using feedback control of an unstable stationary state.
We show that the pulsed regimes observed in free-electron lasers (FELs) can be suppressed using feedback control. By applying tiny parameter perturbations, the feedback allows to keep the systems onto a stationary state that is naturally existing in phase space, but is usually inaccessible because of its unstable nature. We test this method numerically on a master equation derived from the classical iterative model. Then we present the experimental results obtained on the super-ACO FEL. This method is in principle directly applicable to the other free-electron lasers, whose instabilities have a dynamical (deterministic) origin.
Bielawski
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Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Centre d'Etudes et de Recherches Lasers et Applications, FR CNRS 2416, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d'Ascq Cedex, France.
Bruni
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Orlandi
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Garzella
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Couprie
M E
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