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	2014-03-01T02:48:30Z
dc.date.available	2014-03-01T02:48:30Z
dc.date.issued	1997	en
dc.identifier.issn	01604120	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/33865
dc.subject.other	Efficiency correction factor	en
dc.subject.other	Low energy germanium detectors	en
dc.subject.other	Calibration	en
dc.subject.other	Fly ash	en
dc.subject.other	FORTRAN (programming language)	en
dc.subject.other	Gamma ray spectrometers	en
dc.subject.other	Germanium	en
dc.subject.other	Lignite	en
dc.subject.other	Radioisotopes	en
dc.subject.other	Soils	en
dc.subject.other	Spectroscopic analysis	en
dc.subject.other	Radiation detectors	en
dc.subject.other	americium 241	en
dc.subject.other	germanium	en
dc.subject.other	lead 210	en
dc.subject.other	lignite	en
dc.subject.other	radioisotope	en
dc.subject.other	calibration	en
dc.subject.other	computer program	en
dc.subject.other	conference paper	en
dc.subject.other	fly ash	en
dc.subject.other	gamma radiation	en
dc.subject.other	gamma spectrometry	en
dc.subject.other	geometry	en
dc.subject.other	low energy radiation	en
dc.subject.other	mathematical computing	en
dc.subject.other	priority journal	en
dc.subject.other	radiation absorption	en
dc.subject.other	radiation attenuation	en
dc.subject.other	radiation detector	en
dc.subject.other	soil	en
dc.title	An experimental/numerical method for the efficiency calibration of low- energy germanium detectors	en
heal.type	conferenceItem	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.publicationDate	1997	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 self-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 (μ) of both the calibration source and the material to be analysed, calculates the efficiency correction factor. The value of the linear attenuation coefficient (μ) 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 soil samples, lignite, and fly ash, the values of μ 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 210Pb at 46.52 keV and 241Am 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.	en
heal.journalName	Environment International	en
dc.identifier.doi	10.1016/S0160-4120(96)00094-3	en
dc.identifier.volume	22	en
dc.identifier.issue	SUPPL. 1	en
dc.identifier.spage	S93	en
dc.identifier.epage	S99	en