The Evaluation of Gamma Ray Emission Probabilities in the Decay of 56Co

Abstract

56 Co is a radioactive source that is particularly suitable for the calibration of gamma-ray detector efficiencies, as it provides a number of gamma rays of usable intensity with energies up to 3.5 MeV. Data published in 31 papers between 1965 and 2002 for 45 gamma rays with energies between 263 keV and 3612 keV have been reviewed and evaluated. Methods for the evaluation of discrepant data are discussed. Problems with detector efficiency calibrations above 3 MeV have been identified and are addressed.