HARMONICS OF THOMSON BACKSCATTERED X-RAYS

A new concept of harmonic generation of Thomson backscattered X-rays by the angular alignment between the axes of the electron beam and incident laser beam has been proposed. Various properties of the backscattered X-ray harmonic radiation are examined, including the linewidth, radiation pattern on the observation plane, and the behavior of the radiation spectra at ultrahigh laser intensities. It is shown by the simulation results that when the electron beam is deliberately aligned at a suitable small angle in the polarization plane of the linearly polarized laser, both even and odd harmonics along the electron beam axis are generated, which is different from the perfectly aligned case where only odd harmonic radiations peak on the electron-laser axis. Moreover the high harmonics on the angularly aligned electron-laser configuration may have several times higher intensities compared with the axial intensity of the fundamental harmonic in a perfectly aligned case.