Experimental Polarization Control of Thomson Scattering X/γ-ray Source

Abstract: Thomson scattering of intense laser pulses from relativistic electrons allows us to generate high-brightness and tunable-polarization X/{\gamma}-ray pulses. This paper demonstrates the polarization control of the Thomson scattering source experimentally. The polarization of X/{\gamma}-ray is related to incident polarized laser beams, which is controlled by rotating a quarter-wave plate. In the experiment, the polarization of X-ray is determined by recording the spatial distribution of scattered photons, produced by X-ray irradiating on a target. According to modulation curves analysed from experiment results, the conclusion is that the polarization of Thomson scattering source is tunable and controllable. Meanwhile, stokes parameters of X/{\gamma}-ray whose energy varies between tens of keV and MeV are simulated. Considering the paraxial photons, it is showed that the polarization is nearly the same value in a wide range of X-ray energy according to simulation results.