Efficiency calibration of a coaxial HPGe detector-Marinelli beaker geometry using an 152Eu source prepared in epoxy matrix and its validation by efficiency transfer method

Abstract

In this study, an in-house 152Eu calibration source was produced from a custom epoxy matrix with a density of ρ = 1.14 g cm−3, which is chemically stable and durable form after its solidification. The homogeneity of 152Eu in matrix was obtained better than 98%. For a Marinelli beaker geometry, an efficiency calibration procedure was applied to a n-type, coaxial, 78.5% relative efficient HPGe detector in the energy range of 121.7–1408.0 keV by using in-house 152Eu calibration source. Then the measured efficiencies for Marinelli geometry were compared with the results calculated by MEFFTRAN and ANGLE softwares for the validation. Although MEFFTRAN and ANGLE have two different efficiency transfer algorithms to calculate the efficiencies, they usually need to use a reliable and accurate reference efficiency values as input data.Hence, reference efficiency values were obtained experimentally from a multinuclide standard source for the same detector- Marinelli geometry. In the present source characterization, the corrections required for self-absorption and true coincidence summing effects for 152Eu gamma-rays were also obtained for a such close counting geometry condition. The experimental results confirmed the validity of efficiency calculations obtained by MEFFTRAN and ANGLE softwares that are calculation tools. Keywords: Gamma-ray spectrometry, Marinelli geometry, Epoxy, 152Eu, In-house source preparation, Efficiency transfer, MEFFTRAN, ANGLE