HARMONICS OF THOMSON BACKSCATTERED X-RAYS

A new concept of harmonic generation of Thomson backscattered X-rays b y the angular alignment between the axes of the electron beam and inci dent laser beam has been proposed. Various properties of the backscatt ered X-ray harmonic radiation are examined, including the linewidth, r adiation pattern on the observation plane, and the behavior of the rad iation spectra at ultrahigh laser intensities. It is shown by the simu lation results that when the electron beam is deliberately aligned at a suitable small angle in the polarization plane of the linearly polar ized laser, both even and odd harmonics along the electron beam axis a re generated, which is different from the perfectly aligned case where only odd harmonic radiations peak on the electron-laser axis. Moreove r the high harmonics on the angularly aligned electron-laser configura tion may have several times higher intensities compared with the axial intensity of the fundamental harmonic in a perfectly aligned case.