X-ray zero-angle scattering cross section of water

The absolute x-ray scattering cross section for water has been determined at small angles for specimen thicknesses in the range 0.5≤μt ≤6.2 at 20°C and in the temperature range 6 to 75°C for μt = 1.0. The data determined as a function of specimen thickness are in agreement with a new determination of second order multiple scattering. After correction for multiple scattering, the temperature dependent results are in good agreement with the zero-angle scattering cross section computed from fluctuation theory. This result precludes certain cluster models of the structure of liquid water.