Start-Up of a Pulsed Beam Free Electron Laser (FEL) Oscillator

Abstract : A one-dimensional linear analysis is presented of the start-up of an FEL oscillator. The model treats electron beam pulses of arbitrary shape and many significant three dimensional effects are included heuristically. A closed equation is derived for the ensemble averaged electromagnetic energy density matrix which contains the spontaneous emission as a source, and which represents the small gain per pass and losses via coefficient matrices. Numerical solutions are compared with the Stanford experimental results.