Self-oscillations and chaos of free-electron laser oscillators with space charge effects

We investigate the thresholds of periodic and chaotic oscillations in a free-electron laser oscillator by using self-consistent time-dependent one-dimensional Maxwell-Lorentz equations. We consider a Raman-like case where the space charge effects are pronounced. From the parameter dependence of the limit-cycle oscillation frequency, we modify the previous fitting formulas and specify the regimes for the periodic limit-cycle oscillation and for the chaotic oscillation.