Instituto de Radioproteção e Dosimetria (IRD), Comissão Nacional de Energia Nuclear (CNEN), Laboratório Nacional de Metrologia das Radiações Ionizantes (LNMRI), Av. Salvador Allende, s/n° - Barra da Tijuca, CEP 22783-127, Rio de Janeiro, Brazil; Instituto Nacional do Câncer José Alencar Gomes da Silva (INCA), Física Médica, Praça Cruz Vermelha,n° 23, 4° Andar do Prédio Anexo - Lapa, CEP 20230-130, Rio de Janeiro, RJ, Brazil.
Instituto de Radioproteção e Dosimetria (IRD), Comissão Nacional de Energia Nuclear (CNEN), Laboratório Nacional de Metrologia das Radiações Ionizantes (LNMRI), Av. Salvador Allende, s/n° - Barra da Tijuca, CEP 22783-127, Rio de Janeiro, Brazil.
Appl Radiat Isot. 2021 Apr;170:109559. doi: 10.1016/j.apradiso.2020.109559. Epub 2021 Jan 2.
From a commercial supplier, three independent lots of an aqueous solution containing Ra in equilibrium with its deteriorating progeny were considered for standardization, by using live-time anticoincidence counting (LTAC) in the Laboratório Nacional de Metrologia das Radiações Ionizantes (LNMRI) Brazil. The ionization chamber calibration factors were obtained using measurements of independent lots of Ra in LTAC considering the absolute method in order to evaluate the constancy and reproducibility of the standardization. The calibration factors of three high-performance well-type ionization chamber systems and four commercial well-type ionization chambers were determined. The LTAC results showed that lots 2 and 3 were 1069.88 and 1097.44 kBq/kg, with corresponding relative standard uncertainties 0.12% and 0.20%, respectively. The spectrometry method results of each lot value were classified as positive by ANOVA hypothesis testing. The emission probabilities relating to the X- and γ-rays in region from 81 to 830 keV ware determined. Hence, LNMRI can provide calibration services for Ra.
从商业供应商处，考虑了三个含有 Ra 的水溶液的独立批次，这些水溶液处于与其降解产物平衡的状态，以便在巴西国家电离辐射计量实验室（LNMRI）中使用实时符合计数（LTAC）进行标准化。使用 LTAC 测量独立批次的 Ra 来获得电离室校准因子，考虑绝对方法以评估标准化的恒定性和可重复性。确定了三个高性能的井型电离室系统和四个商业井型电离室的校准因子。LTAC 的结果表明，第 2 批和第 3 批分别为 1069.88 和 1097.44 kBq/kg，相应的相对标准不确定度分别为 0.12%和 0.20%。每个批次值的光谱法结果通过方差分析假设检验被归类为阳性。确定了 X 和 γ射线在 81 到 830 keV 区域的发射几率。因此，LNMRI 可以为 Ra 提供校准服务。
