Bremsstrahlung‐Based Imaging and Assays of Radioactive, Mixed and Hazardous Waste

A new nondestructive accelerator based x‐ray fluorescence (AXRF) approach has been developed to identify heavy metals in large‐volume samples. Such samples are an important part of the process and waste streams of U.S Department of Energy sites, as well as other industries such as mining and milling. Distributions of heavy metal impurities in these process and waste samples can range from homogeneous to highly inhomogeneous, and non‐destructive assays and imaging that can address both are urgently needed. Our approach is based on using high‐energy, pulsed bremsstrahlung beams (3–6.5 MeV) from small electron accelerators to produce K‐shell atomic fluorescence x‐rays. In addition we exploit pair‐production, Compton scattering and x‐ray transmission measurements from these beams to probe locations of high density and high atomic number. The excellent penetrability of these beams allows assays and images for soil‐like samples at least 15 g/cm2 thick, with elemental impurities of atomic number greater than app...