Standardization of Ca-45 radioactive solution by tracing method

Abstract

The procedure followed by the Laboratório de Metrologia Nuclear (LMN) at the IPEN, in São Paulo, for the standardization of the 45Ca is described. The activity measurement was carried out in a 4πβ-γ coincidence system, by the tracing method. The radionuclide chosen as the β-γ emitting tracer nuclide was 60Co because of its end-point beta-ray energy which is close to 45Ca. Six sources were prepared using a 1:1 ratio (β-pure and β-γ) dropped directly on the Collodion film, and other two solutions of 45Ca + 60Co were mixed previously using a 1:1 and 1:2 ratio before making the radioactive sources. The activity of the solution was determined by the extrapolation technique. The events were registered using a Time to Amplitude Converter (TAC) associated with a Multi-channel Analyzer.