Transport of Thermal Neutrons in D2O in the Temperature Range 5 to 60°C Based on a New Scattering Kernel

Abstract

A new scattering kernel for heavy water has been proposed. The kernel takes into account the chemical binding energy effects and also includes the rotational and intramolecular vibrational modes. Using this scattering kernel, various neutron transport processes in the temperature range 5 to 60°C have been studied and compared with the corresponding experimental results. The calculated results include 1. total neutron scattering cross section at 20°C2. asymptotic decay of neutron pulses in the temperature range 5 to 60°C and temperature variation of the diffusion coefficient and diffusion cooling coefficient3. time-dependent spectra inside finite-sized assemblies of heavy water at 20 and 43.3°C4. thermalization time5. diffusion length and space-dependent study in pure and poisoned assemblies of heavy water. The calculated results are in good agreement with the experimental results. At some places notable differences are observed between the results obtained using our scattering kernel and those based on the Honeck kernel.