Analysis of an FEL oscillator at zero detuning length of an optical cavity

Nishimori, Nobuyuki

Nuclear Instruments and Methods in Physics Research A, 528(1-2), p.34 - 38, 2004/08

https://doi.org/10.1016/j.nima.2004.04.013

The sustained saturation in an FEL oscillator at zero detuning of an optical cavity (=0) is studied analytically. The FEL field at =0 is characteristic of self-amplified spontaneous emission (SASE) FEL. For both cases, the field is composed of the forward incoherent and subsequent coherent states. The coherent field at =0 evolves with round trips due to the lethargy. The field at saturation is similar to that of the leading edge of SASE FEL with high electron beam density. It is found that the peak intensity and the pulse length of the saturation field scale with fundamental FEL parameter and an optical cavity loss.