Analysis of the Performance of LaBr3 Detectors for Fresh Fallout Response (PERLAD)
M. Dowdall, Kari Peräjärvi, Tero Karhunen, Sara Ehrs, Charlotte Alfast Espensen, Gísli Jónsson,
With spectral resolution of approximately 3 % at 662 keV, LaBr3 scintillators exhibit substantial improvements over sodium iodide scintillators with a resolution of 6-7 % for crystals of comparable sizes and fast emission relative to NaI and HPGe. LaBr3 crystals are available in sizes up to 3×3 inches and this availability has led to an increase in the prevalence of such detectors for a variety of purposes. These include as hand held detectors for in-field use, in conventional laboratory situations and for direct monitoring of radioactive contaminants. Direct measurement of airborne contamination is made complicated for any detector type due to the necessity to generate efficiency data for a geometry which is in effect impossible to replicate. While estimates of efficiency may be obtained using deterministic calculations, the need to account for elements of the detector assembly aside from the detector complicates the process. This project investigates the use of such detectors for the direct measurement of airborne and ground deposited contamination using Monte Carlo simulation for the assessment of efficiency in field use configurations.
LaBr3, efficiency, Monte Carlo, emergency preparedness