Minimum Detectable Activity in gamma spectrometry and its use in low level activity measurements

• Published in: Applied radiation and isotopes Vol. 114; pp. 28 - 32
• Main Authors: Done, L., Ioan, M-R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2016
• Subjects: Algorithms; Calculus; Characteristic limits; Density; Homogeneity; HPGe detector; Low level; Low level activity measurements; Mathematical analysis; Minimum Detectable Activity (MDA); Spectrometry; Spectroscopy; Minimum Detectable Activity (MDA); Characteristic limits; Low level activity measurements; HPGe detector
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2016.05.004

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/cm3. Choosing this type of matrix was done because of its high homogeneity. •Three different MDA algorithms were applied to gamma spectrometry measurements.•The measurements were performed using two HPGe detectors.•MDA performances of the two spectrometric systems were compared.•The measured samples had different geometries and contained a mixture of radionuclides.•MDA was studied also as a function of measuring time.