Impact of an external radiation field on handheld XRF measurements for nuclear forensics applications

X-ray fluorescence (XRF) is an attractive technique for nuclear forensics applications. We evaluated a handheld XRF device by applying an external radiation field (10 mR/h–17 R/h) using two types of radiography sources: a 60Co radiography camera for high-energy gamma emissions and an 192Ir radiography camera for several low-energy gamma (0.604, 0.468, and 0.317 MeV) and decay daughter X-ray emissions. External radiation tests proved that radiation, in general, has a significant effect on the dead time or background at dose rates over 1 R/h for both the 192Ir and 60Co sources.