Saturation mechanism for a storage-ring free-electron laser

Abstract

Equilibrium and dynamical properties of a storage-ring free-electron laser are shown as resulting from the combined effects of two different saturation mechanisms. The first one is the laser-induced energy spread of the electron beam. The second mechanism is due to an imperfect longitudinal synchronism between the electron and laser pulses. Consequences are briefly described.

Suppression of self-pulsing instabilities in free-electron lasers using delayed optical feedback

“…At larger detunings, another instability leads to full scale modulations of the envelope of the laser pulse train. This regime, called ''macropulse instability'' in the case of SR-FEL, has a deterministic origin [5,11,12], and shares deep similarities with classical mode-locked lasers [9,13].…”

“…In the so-called oscillator configuration, the laser pulses experience round-trips in an optical cavity, and are synchronously pumped by the electron bunches. The FEL dynamics is mainly governed by the synchronism between the optical pulses and the electron bunches either circulating in a storage ring [3,4] or coming from a linear accelerator [5][6][7][8].…”

Lasers à électrons libres de courtes longueurs d'onde : état de l'art et perspectives

“…Cinq LELs sur anneau de stockage fonctionnent actuellement : Super-ACO en France [6], ELETTRA (collaboration européenne) en Italie [7], NIJI-4 [8] et UVSOR [9] au Japon, DUKE [10] aux USA, et ils ont montré un régime « CW à l'échelle de la ms, outre la répétition à haute cadence des micro-impulions (MHz). Des systèmes de contre-réaction longitudinale furent mis en oeuvre sur les LELs de Super-ACO [11] et de UVSOR [12], réduisant les fluctuations d'intensité à 1 % et compensant le jitter du laser.…”

Compton backscattering of intracavity storage ring free-electron laser radiation

“…[3] We define the wiggler parameter K i as an example to illustrate the C.B.P. brightness, the case of the Super ACO storage ring FEL at Saclay [8]. Using the parameters in Tb.…”