YAMAZAKI, I.M.KOSKINAS, M.F.MOREIRA, D.S.SEMMLER, R.BRANCACCIO, F.DIAS, M.S.2020-07-212020-07-212020YAMAZAKI, I.M.; KOSKINAS, M.F.; MOREIRA, D.S.; SEMMLER, R.; BRANCACCIO, F.; DIAS, M.S. Primary standardization and determination of gamma ray emission intensities of Ho-166. <b>Applied Radiation and Isotopes</b>, v. 164, p. 1-6, 2020. DOI: <a href="https://dx.doi.org/10.1016/j.apradiso.2020.109237">10.1016/j.apradiso.2020.109237</a>. Disponível em: http://repositorio.ipen.br/handle/123456789/31344.0969-8043http://repositorio.ipen.br/handle/123456789/31344The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN-CNEN/SP, in S~ao Paulo, for the primary standardization of 166Ho is described. The activity of 166Ho was determined by the efficiency extrapolation technique applied to a 4πβ(PC)-γ coincidence system using a gas flow proportional counter in 4π geometry coupled to a 76 x 76 mm NaI(Tl) crystal. The results for the γ-rays intensities at 80.57 and 1379.45 keV were 0.0651(11) and 0.00904(11), respectively.1-6openAccessstandardizationgamma radiationemissionholmium 166coincidence methodscounting techniquesfour-pi countingx-ray sourcesmeasuring instrumentsradioisotopesArtigo de periódico16410.1016/j.apradiso.2020.1092370000-0001-7733-01530000-0001-8407-9833https://orcid.org/0000-0003-2478-5757https://orcid.org/0000-0001-7733-0153https://orcid.org/0000-0001-8407-983334.9644.00