Differential cross sections for elastic scattering of tagged, monochromatic photons have been measured on a water target for incident photon energies between 21.7 and 27.5 MeV and at scattering angles of 135° and 45°. These data are interpreted in terms of the total photoabsorption cross section in the region of the giant dipole resonance. We find that the data are reasonably consistent with previous direct measurements of the total photoabsorption cross section and inconsistent with more recent determinations of the total cross section by summing the various partial cross sections.

• Received 6 February 1987

DOI:https://doi.org/10.1103/PhysRevC.35.2005