Semi-analytical model of self-amplified spontaneous-emission free-electron lasers, including diffraction and pulse-propagation effects

We use the high-gain free-electron laser logistic equation to describe the field evolution from spontaneous emission to saturation in the self-amplified spontaneous-emission regime. The model we present is capable of including the effects of diffraction, beam qualities, and pulse propagation. (C) 2004 American Institute of Physics.