Bound-state Compton scattering of linearly polarized photons

We present a theoretical study of Compton scattering of x-rays and γ rays by a K -shell electron. Special attention is paid to the double-differential cross section and polarization of the scattered photons for linearly polarized incident photons. To investigate these observables, we employ the scattering matrix ( S − matrix ) approach based on relativistic Green's functions. The S − matrix results are moreover compared with predictions of the free-electron and impulse approximations, allowing us to assess the role of electron binding effects. Detailed calculations are carried out for hydrogenlike Ne 9 + and Pb 81 + targets over a wide range of incident photon energies and scattering angles. The calculations reveal kinematic regimes in which the impulse approximation agrees reasonably well with the S − matrix results. We also explore the polarization of scattered photons for slightly depolarized incident radiation, including the highly sensitive case of scattering at 90 ∘ .