MAIDANA, N.L.DIAS, M.S.KOSKINAS, M.F.2014-11-172014-11-182015-04-022014-11-172014-11-182015-04-02MAIDANA, N.L.; DIAS, M.S.; KOSKINAS, M.F. Primary standardization of sup(242)Am radioactive sources. In: REGIONAL CONGRESS ON RADIATION PROTECTION AND SAFETY, 5th, REGIONAL IRPA CONGRESS, Apr. 29 - May 4, 2001, Recife, PE. <b>Proceedings...</b> Disponível em: http://repositorio.ipen.br/handle/123456789/15242.http://repositorio.ipen.br/handle/123456789/15242The procedure followed by the Laboratório de Metrologia Nuclear in São Paulo, Brazil, for the standardization of 242gAm is described. The calibration system was composed of a 4π gas-flow proportional counter coupled to a pair of NaI(Tl) crystals operating in coincidence. The samples were produced by irradiating dried aliquots of 241Am with thermal and epithermal neutrons at the IEA-R1 research reactor. The efficiency tracer technique has been applied using 60Co as tracer. The beta detection efficiency was changed by external absorbers and extrapolated to unity by linear least square fitting applying covariance methodology.openAccessamericium 242standardizationproportional countersnai detectorscoincidence methodscobalt 60americium 241beta detectionradioactivityTexto completo de eventohttps://orcid.org/0000-0001-8407-9833https://orcid.org/0000-0003-2478-5757