Determination of the intensity of X- and gamma-ray emissions in the decay of 153Sm

The activity of a 153Sm solution was determined by means of liquid scintillation counting and an ionization chamber. Several accurately calibrated X- and gamma-ray spectrometers were used to measure point sources. The use of different detectors results in improvements to the accuracy of the data around 100 keV where the efficiency curve changes significantly. Photon emission intensities have been derived for the main X- and gamma-rays, and the 103-keV emission has a measured intensity of (29.07 (20)) per 100 disintegrations.