A Theory of Pulsed Neutron Experiments in Polycrystalline Media

A theory of pulsed neutron experiments for thermal, nonmultiplying polycrystalline media is presented. Existence theorems for discrete eignevalues are examined together with the role of various continua. It is found that discrete eigenvalues can exist with values greater than the minimum collision frequency. A new continuum contribution, directly related to elastic scattering, provides a bound for the discrete eigenvalues in small assemblies.