Neutron Wave Propagation Across a Temperature Discontinuity—Multigroup Approach

Calculations of neutron wave propagation across a temperature discontinuity in graphite using a multigroup approach are reported. Diffusion, as well as thermalization properties of the medium, are investigated near the interface. As the interface is crossed from the higher to the lower temperature region, a depletion of sub-Bragg neutrons is observed. There is a buildup of neutrons as one crosses the interface from the lower to the higher temperature side.