Collimated spectroscopy for specific activity determination behind a shield wall

When radioactive materials are placed behind shield walls where the actual specific activity is not known (such as high dose rate waste containers or highly contaminated glove boxes), remote assay can be highly desirable. This paper walks through a theoretical analysis technique whereby an assay calculation can be carried out via collimated spectroscopy. This is done using standard approximations of homogeneous sources, source matrices, perfect collimation and accurately known geometric material distributions. All solutions are given in closed form when appropriate approximating functions are used.