title: Absolute activity of (133)Ba by liquid scintillation coincidence counting using the 4pi(e,X)-gamma extrapolation technique.
abstract: 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.
authors: National Metrology Institute of South Africa, Cape Town, South Africa. bsimpson@nmisa.org
authors: B R S
authors: BR
authors: Simpson
authors: W M
authors: WM
authors: van Wyngaardt