title: Standardization of (99m)Tc by means of a software coincidence system.
abstract: The procedure followed by the Nuclear Metrology Laboratory, at IPEN, for the primary standardization of (99m)Tc is described. The primary standardization has been accomplished by the coincidence method. The beta channel efficiency was varied by electronic discrimination using a software coincidence counting system. Two windows were selected for the gamma channel: one at 140 keV gamma-ray and the other at 20 keV X-ray total absorption peaks. The experimental extrapolation curves were compared with Monte Carlo simulations by means of code ESQUEMA.
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares IPEN-CNEN/SP, Centro do Reator de Pesquisas-CRPq, C.P. 11049, Pinheiros, 05422-970, São Paulo, SP, Brazil.
authors.forename: A B
authors.initials: AB
authors.lastname: Brito
authors.forename: M F
authors.initials: MF
authors.lastname: Koskinas
authors.forename: F
authors.initials: F
authors.lastname: Litvak
authors.forename: F
authors.initials: F
authors.lastname: Toledo
authors.forename: M S
authors.initials: MS
authors.lastname: Dias
mesh_terms: D001938:Brazil; D006207:Half-Life; D038622:Internationality; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods* / Q000592:standards*; D012015:Reference Standards; D012016:Reference Values; D012984:Software; D013051:Spectrometry, Gamma / Q000592:standards*; D013667:Technetium / Q000032:analysis* / Q000592:standards*
chemical_list: D013667:Technetium