Prompt γ‐Neutron Activation Analysis

Abstract

Prompt γ‐neutron activation analysis (PGNAA) is a multielemental analytical technique based on the detection of γ‐rays emitted by excited nuclei following neutron radioactive capture or neutron inelastic scattering. The accumulated count rate relative to the γ‐ray energy characteristic of a certain isotope depends on its concentration. Measurements take place during sample irradiation. The technique can provide accurate information on the elemental composition of materials in a broad range of cases: raw materials, mineral exploration, contaminants, detection of forbidden products, such as drugs and explosives, inspection of containers and applications in health care. Among the main advantages of the PGNAA technique are: faster results; nondestructiveness; flexible sample requirements; bulk sample analysis; in situ application by direct on‐line measurement; detectable unique signatures for most elements; improved accuracy for short‐lived elements; low residual activity. On the other hand, the most significant limitations are: higher detection limits (DLs) as compared with delayed γ‐neutron activation analysis (DGNAA); longer irradiation times; single (one‐cycle) sample irradiation; impracticability of enhancing a specific isotope contribution by radiochemical or physical (half‐life) separation techniques; requirement for relatively larger samples.