Compton suppression for neutron activation analysis applications at the National Institute of Standards and Technology (NIST)

A central high purity germanium (HPGe) detector is surrounded by guard detectors. Counts picked up by both detectors are Compton or escape events, while those detected only by the HPGe are photopeaks considered useful for analysis. The electronics system accepts counts detected only by the HPGe detector and rejects ones in coincidence with the guard detectors. Analysis of calibrated Cs-137, Na-24 and Co-60 sources demonstrated the effective Compton suppression for the systems. Examination of certified reference materials, activated in the reactor, demonstrated the experimental readiness of the systems.