Gamma-Ray Transmission through Multiple Layers

A review is presented on the γ-ray transmission problem through multiple layered shields. In Chap. II, an introductory explanation is given on the behavior of photons in stratified slabs. Several illustrations of energy spectra, angular distributions of photons and buildup factors in the slabs provide an outline of the phenomena involved. In Chap. III, an extensive survey of theoretical treatments is made to examine the adaptability of the methods to the γ-ray multilayer problem. The survey includes several methods for numerically solving the Boltzmann transport equation, the Monte Carlo method, the successive scattering method, as well as various transmission operator and invariant imbedding methods. Apart from the Monte Carlo method, only a few of the methods are applicable to the multilayer problem of γ-rays. The result of the survey is further summarized in a table. Chap. IV gives a brief description of the relevant experiments. The survey brings into relief the lack of experiments with source energies above the 60Co level.