Measured Total Cross Sections Of Slow Neutrons Scattered By Gaseous And Liquid H-2(2)

The total scattering cross sections for slow neutrons with energies E in the range 300 neV to 3 meV for gaseous and liquid ortho-H-2(2) have been measured. The cross sections for H-2(2) gas are found to be in excellent agreement with both the Hamermesh and Schwinger and the Young and Koppel models. For liquid H-2(2), we confirm the existing experimental data in the cold neutron range and the discrepancy with the gas models. We find a clear 1/root E' dependence at low energies for both states. A simple explanation for the liquid H-2(2) cross section is offered.