A Transport Theory of Neutron Wave Propagation in Polycrystalline Media

The propagation of neutron waves in polycrystalline moderators is analyzed via a modeled velocity-dependent transport theory. Analytical results are made possible by the use of a simple model of the scattering kernel. Particular attention is devoted to the interpretation of neutron wave experiments performed in graphite parallelepipeds. It is found that, while a plane wave mode is not always dominant asymptotically in polycrystalline materials, a meaningful experiment can be performed provided certain restrictions on detector position and source frequency are observed.