Abstract The interaction of photons with relativistic electrons constitutes a fundamental electromagnetic process whose polarization transfer mechanics remain incompletely characterized. We report the first systematic measurement of spatial polarization distribution for γ rays generated via 45○ slant Inverse Compton Scattering (ICS) between linearly polarized 0.117 eV photons and 3.5 GeV electrons, performing full 2D mapping of intensity, Angle Of Polarization (AOP), and Degree Of Polarization (DOP). Measurements reveal an asymmetric beam profile along the laser’s polarization direction that resembles 180○ backward ICS observations. The central beam region exhibits DOP near 1.0 with AOP rigidly aligned at 45○, while peripheral regions display complex non-uniform polarization distributions. These findings confirm quantum electrodynamics predictions of near-complete polarization transfer along the beam axis in slant geometries, thus establishing slant scattering as a viable alternative to head-on configurations for generating high DOP γ rays.
Chen et al. (Fri,) studied this question.