Calibration of two portable detection devices for in vivo measurements of high-energy photon emitters incorporated by humans in accidental situations

Abstract

This work presents the evaluation of the applicability and sensitivity of two portable detection devices specially designed for in vivo measurement of high-energy photon emitters incorporated by humans. The calibration was performed at the In-Vivo Monitoring Laboratory of the IRD. The equipment consist of a NaI(Tl) 3”x3” and a NaI(Tl) 3”x1.5” scintillation detectors assembled on tripods. The detectors and their compact associated electronics are connected via USB cable to a portable PC. Spectrum acquisition and analysis are controlled by specific commercially available software. The calibrations were performed using a standard liquid source of 152Eu contained in 3.3 L polyethylene bottles. The evaluation of the systems is based on the estimation of the minimum committed effective doses associated to the minimum detectable activities, calculated using current biokinetic and dosimetric models available in the literature. The dose detection limits for selected radionuclide of interest in an emergency scenario have shown to be far below 1 mSv, allowing the system to be useful in accident situation.