Simpson B R S, van Wyngaardt W M
National Metrology Institute of South Africa, Cape Town, South Africa.
Appl Radiat Isot. 2008 Jun-Jul;66(6-7):929-33. doi: 10.1016/j.apradiso.2008.02.036. Epub 2008 Feb 8.
The Technical Committee for Ionizing Radiation (TCRI) of the Asia Pacific Metrology Programme (APMP) recently organized a regional key comparison of activity measurements of the radionuclide (133)Ba. This paper reports on absolute measurements made at the National Metrology Institute of South Africa (NMISA) by the coincidence extrapolation technique, with liquid scintillation counting (LSC) comprising the 4pi channel. A detection efficiency analysis was undertaken to predict the maximum efficiency likely to be achieved and to confirm that the method does indeed provide the source disintegration rate for (133)Ba. Various experimental and data analysis difficulties to be aware of are discussed in the paper.
亚太计量规划组织（APMP）的电离辐射技术委员会（TCRI）最近组织了一次放射性核素（133）Ba活度测量的区域关键比对。本文报道了南非国家计量研究所（NMISA）采用符合外推技术进行的绝对测量，其中液体闪烁计数（LSC）包括4π通道。进行了探测效率分析，以预测可能达到的最大效率，并确认该方法确实能提供（133）Ba的源衰变率。文中讨论了需要注意的各种实验和数据分析难点。
