Elastic Scattering of 1.33-MeV Photons from Lead and Uranium

Abstract

Differential cross sections for the elastic scattering of 1.33-MeV photons from lead and uranium have been measured at angles ranging from 12 to 60\ifmmode^\circ\else\textdegree\fi{}, using a lithium-drifted germanium detector. Available calculations of the various elastic scattering amplitudes are briefly reviewed and an argument is presented to establish the relative phases between the two polarization components of the real scattering amplitudes. Those relative phases and the relative phases among the amplitudes of the various scattering processes permit the addition of the amplitudes to calculate theoretical cross sections. Discrepancies exist between the measured and theoretical cross sections. Suggestions by several authors for resolving these discrepancies are discussed and the need for further theoretical work is indicated.