title: Minimum Detectable Activity in gamma spectrometry and its use in low level activity measurements.
abstract: In this paper there are described three different algorithms of Minimum Detectable Activity (MDA) calculus, and its use in high resolution gamma spectrometry. In the first part, few introductive theoretical aspects related to the MDA are presented. Further, the theory was applied to real gamma rays spectrometry measurements and the results were compared with the activities reference values. Two different gamma spectrometry systems, both of them using High Purity Germanium (HPGe) detectors, but having different efficiencies, were used. Samples having different geometries and radionuclides content were measured. The measured samples were made by dissolving of some acids containing anthropogenic radionuclides in water, obtaining a density of 1g/cm(3). Choosing this type of matrix was done because of its high homogeneity.
authors.affiliation: Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH), 30 Reactorului Str., Bucharest-Magurele, Ilfov County, Code 077125, Romania.
authors.forename: L
authors.initials: L
authors.lastname: Done
authors.affiliation: Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH), 30 Reactorului Str., Bucharest-Magurele, Ilfov County, Code 077125, Romania. Electronic address: razvan.ioan@nipne.ro.
authors.forename: M-R
authors.initials: MR
authors.lastname: Ioan
keywords: Characteristic limits; HPGe detector; Low level activity measurements; Minimum Detectable Activity (MDA)