Geometry factors and flux corrections in neutron activation analysis

Two possible sources of error in neutron activation analysis are variations in neutron flux over the length, width, and height of a sample and geometry factors during counting of the activated sample. Development of a sample preparation, handling, and analysis system designed to minimize these two problems as well as reducing contamination problems is described. The procedure basically involves four steps: (1) spotting a known volume of sample solution or standard solution on a filter disc and allowing it to dry in a laminar-flow clean bench; (2) sealing the disc between two layers of plastic; (3) irradiation; and (4) counting. (LK)