Numerical Simulation of Nonlinear Effects in a Laser–Electron X-Ray Source

Abstract

We investigate the interaction between laser and electron beams in a laser–electron source using a classical nonlinear model that enables calculation of the parameters of the generated X-ray or gamma-ray radiation, including total flux, spectral brilliance, and polarization. The X-ray spectral brilliance of the fundamental and higher harmonics is calculated as a function of photon energy, observation angle, and laser pulse energy for a set of probable electron-accelerator and laser-system parameters. Nonlinear effects are shown to cause significant spectral broadening of the fundamental harmonic, which can markedly reduce the spectral selectivity of the source and may require additional measures for spectral narrowing. On the other hand, the contribution of higher nonlinear harmonics to spectral degradation of the radiation is insignificant because of their low intensity.