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Gaithersburg, MD, United States

Lepy M.C.,CEA Saclay Nuclear Research Center | Pearce A.,Radioactivity Group | Sima O.,University of Bucharest
Metrologia | Year: 2015

High resolution gamma-ray spectrometry is a well-established metrological technique that can be applied to a large number of photon-emitting radionuclides, activity levels and sample shapes and compositions. Three kinds of quantitative information can be derived using this technique: detection efficiency calibration, radionuclide activity and photon emission intensities. In contrast to other radionuclide measurement techniques gamma-ray spectrometry provides unambiguous identification of gamma-ray emitting radionuclides in addition to activity values. This extra information comes at a cost of increased complexity and inherently higher uncertainties when compared with other secondary techniques. The relative combined standard uncertainty associated with any result obtained by gamma-ray spectrometry depends not only on the uncertainties of the main input parameters but also on different correction factors. To reduce the uncertainties, the experimental conditions must be optimized in terms of the signal processing electronics and the physical parameters of the measured sample should be accurately characterized. Measurement results and detailed examination of the associated uncertainties are presented with a specific focus on the efficiency calibration, peak area determination and correction factors. It must be noted that some of the input values used in quantitative analysis calculation can be correlated, which should be taken into account in fitting procedures or calculation of the uncertainties associated with quantitative results. It is shown that relative combined standard uncertainties are rarely lower than 1% in gamma-ray spectrometry measurements. © 2015 BIPM & IOP Publishing Ltd. Source

Pollanen R.,Radiation and Nuclear Safety Authority | Siiskonen T.,Radiation and Nuclear Safety Authority | Ihantola S.,Radiation and Nuclear Safety Authority | Toivonen H.,Radiation and Nuclear Safety Authority | And 3 more authors.
Journal of Radioanalytical and Nuclear Chemistry | Year: 2011

High-resolution alpha spectrometry was applied for the activity determination of 10 reference sources containing different amounts of 238Pu, 239Pu, 240Pu and 242Pu. They were analyzed as blind sources using a novel spectrum analysis tool ADAM. The information needed in the spectrum unfolding was taken only from the spectrum under investigation, and no tracers were applied. Therefore, a Monte Carlo program AASI was used to compute geometrical detection efficiency of the measurement setup. All reported activities corresponded to those of the reference sources within expanded uncertainty. The developed tools can be used for the activity determination in nondestructive alpha spectrometry or when the radionuclide composition does not change during the sample processing. © Akadémiai Kiadó, Budapest, Hungary 2011. Source

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