Experiments on the elastic scattering of photons in the energy range between 20 keV and 3.5 MeV as test of theoretical predictions of relativistic quantum mechanics and quantum electrodynamics

At a photon energy 2.754 MeV differential cross sections for elastic photon scattering were measured at scattering angles between 300 and 600 for different elements. For the scattering experiments, which were performed in the second part of this thesis with a multiline source at a fixed scattering angle of 7.70, for the applied scatterers lead and tin a good agreement between the measured and the theoretical cross sections could be stated. The contribution of the Delbrueck scattering could be for the first time confirmed experimentally for this small scattering angle. In the framework of the measurement accuracy could be shown that for photon energies <3 MeV and small scattering angles Coulomb corrections can be neglected against the dominating Rayleigh amplitudes. In the third part of the present thesis the Rayleigh scattering on the rare gas xenon was measured in the energy range 28-45 keV at scattering angles of 600, 900, and 1200 for the first time with polarized synchrotron radiation. (orig./HSI)