SASE FEL Storage Ring
  We explore the possibility of operating a SASE FEL with a Storage Ring. We use a semi-analytical model to obtain the evolution inside the undulator by taking into account the interplay on the laser dynamics due to the induced energy spread and to the radiation damping. We obtain the Renieri's limit for the stationary output power and discuss the possibility of including in our model the effect of the beam instabilities. 
G. Dattoli, E. Di Palma, A. Petralia and J. V. Rau
physics.acc-ph