Generation of X-Ray Radiation in Free-Electron Lasers with Two-Frequency Undulators

Abstract

The possibility of creating an x-ray laser with a two-frequency undulator with the help of the phenomenological model of a single-pass free-electron laser (FEL) that takes into account the beam characteristics and the undulator field is studied. The model is used to analyze the FEL dynamics, and the simulation results are compared with the experimental data. The advantages of using a two-frequency undulator in the single-pass FEL and the possibility of generating powerful x-ray radiation in it are demonstrated. The evolution of power of higher-harmonic generation in the FEL and the bunching coefficient at wavelengths of these harmonics are studied. The possibility of their further amplification until saturation in a cascade FEL matched to higher harmonics of the two-frequency undulator is demonstrated.