Numerical Simulation of Nonstationary Processes in Free Electron Lasers

A computational scheme is developed to integrate a set of self-consistent equations describing the evolution of the field structure in free electron lasers. The proposed scheme is fourth-order accurate in space and third-order accurate in time. The boundedness of solution is provided by a number of integrals in the scheme. Stationary and pulse electron injection regimes are investigated. In both cases the scheme permits effective calculation of the following regimes: (a) stationary single-mode generation (or, correspondingly, generation of identical pulses), (b) periodic self-modulation, (c) stochastic self-modulation.