Abstract and subjects
Samarium-153 (
153
Sm
) is a short-lived radionuclide that decays to stable europium-153 via beta emission, with subsequent de-excitation via gamma emission and internal conversion. Historical measurements of
153
Sm
by gamma spectrometry and beta liquid scintillation counting have shown a low bias compared to beta proportional counting. In order to investigate this, four national laboratories jointly conducted an experimental inter-comparison exercise on a certified
153
Sm
sample, created from neutron activation of samarium-152. Radiometric measurements were conducted using gamma spectrometry, liquid scintillation counting, gas proportional counting, and passivated implanted planar silicon detectors and compared across the four institutions against the certified value. The results from this experiment are presented together with a number of conclusions which suggest that the current published cumulative fission yield for
153
Sm
, as used by many laboratories, is approximately 15% high and is the likely cause of the previously observed bias.