Delbrueck and Rayleigh scattering by uranium investigated at photon energies between 0.1 and 1.5 MeV

using radioactive sources, high-precision differential cross sections for elastic scattering of photons by U(ZETA=92) have been measured for energies between 0.1 and 1.5 MeV and scattering angles ranging from 150 to 1500. The experimental results have been interpreted in terms of Rayleigh, nuclear Thomson, nuclear resonance and Delbrueck scattering. Below 0.5 MeV the Rayleigh theory based on the second-order S matrix and Dirac-Hartree-Fock-Slater wavefunctions has been confirmed to within 3% on average. At energies between 0.9 and 1.5 MeV definite evidence has been obtained for dispersive Delbrueck scattering. The excellent agreement between experiment and lowest-order Delbrueck theory shows that Coulomb corrections are small at these energies. (author)