A feasibility study of a coincidence counting approach for PGNAA applications

Prompt gamma-ray nutron activation analysis (PGNAA) has an inherently low s ignal-to-noise (S/N) ratio primarily because of the large background (noise ) associated with it. Most elements emit a significant fraction of their pr ompt gamma rays in coincidence with one or more other prompt gamma rays. Th is paper reports on initial efforts to use coincidence counting in PGNAA to significantly reduce the several sources of background and thereby increas e the SIN ratio. An added benefit is the elimination of the often dominant hydrogen prompt gamma-ray spectrum which emits only a single prompt gamma r ay with an energy of 2.223 MeV. Preliminary results are given for both in s itu bulk analysis applications with a Cf-252 neutron source and for nuclear reactor thermal neutron beam applications for small laboratory samples. (C ) 2000 Elsevier Science Ltd. All rights reserved.