An experimental/numerical method for the efficiency calibration of low-energy germanium detectors

Anagnostakis, MJ; Simopoulos, SE

dc.contributor.author	Anagnostakis, MJ	en
dc.contributor.author	Simopoulos, SE	en
dc.date.accessioned	2014-03-01T01:11:40Z
dc.date.available	2014-03-01T01:11:40Z
dc.date.issued	1996	en
dc.identifier.issn	0160-4120	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/11771
dc.subject	Gamma Ray	en
dc.subject	Low Energy	en
dc.subject	Numerical Method	en
dc.subject	Numerical Technique	en
dc.subject	Fly Ash	en
dc.subject	FORTRAN	en
dc.subject.classification	Environmental Sciences	en
dc.subject.other	SELF-ABSORPTION	en
dc.subject.other	SAMPLES	en
dc.title	An experimental/numerical method for the efficiency calibration of low-energy germanium detectors	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0160-4120(96)00094-3	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0160-4120(96)00094-3	en
heal.language	English	en
heal.publicationDate	1996	en
heal.abstract	Several radionuclides emit significant gamma rays at energies below 80 keV, which in many cases are essential for their detection in radioenvironmental assays. Gamma spectroscopic analysis at this energy region is conducted using planar Low Energy Germanium detectors, with high and almost constant efficiency in the energy region between 20 and 80 keV. In the analysis of solid and liquid samples, with these detectors, the count rate is highly affected by the intense serf-absorption of the low energy photons. Thus, the difference in the absorption properties between the calibration source and the sample requires the introduction of an efficiency correction factor. A method applicable for cylindrical geometries was adapted for the determination of the above correction factor using a newly developed experimental-numerical. technique and a Fortran program. This program, using as input the source-to-detector geometry and the values of the linear attenuation coefficient (mu) of both the calibration source and the material to be analysed, calculates the efficiency correction factor. The value of the linear attenuation coefficient (mu) needed for this calculation is being experimentally estimated for each material to be analysed. The technique has been cross-checked using standard materials. According to the results obtained, in the case of surface sail samples, lignite, and fly ash, the values of mu ranges from 0.2 to 0.9 cm(-1). This leads to efficiency correction factors, for the geometry used and a 4M HCl mixed radionuclide calibration source, in the range of 0.5 to 1.2 for the photons emitted by Pb-210 at 46.52 keV and Am-241 at 59.54 keV. The correction factor for 185.99 keV photons is slightly lower than 1.0, even for the most absorbing of the materials analysed. Copyright (C) 1996 Elsevier Science Ltd.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	ENVIRONMENT INTERNATIONAL	en
dc.identifier.doi	10.1016/S0160-4120(96)00094-3	en
dc.identifier.isi	ISI:A1996XK59200012	en
dc.identifier.volume	22	en
dc.identifier.spage	S93	en
dc.identifier.epage	S99	en