Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1878656 | Applied Radiation and Isotopes | 2014 | 4 Pages |
•We show how the instrument efficiencies are dependent on filtering.•We examine the isotropy of β-particle fluences and observe the angular dependence.•We explain discrepant instrument efficiencies of pure 90Y source and filtered 90Sr/90Y.
If high-energy beta particles are required for the efficiency determination of surface contamination monitors, wide area filtered 90Sr/90Y sources are commonly used instead of short-lived pure 90Y sources. In this work we show how the instrument efficiencies are dependent on filtering. Significant difference in the instrument efficiencies between filtered 90Sr/90Y and pure 90Y source was obtained due to spectral degradation of the beta emission spectrum. Changes in the β-particle spectra were investigated by the use of a plastic scintillation spectrometer and the anisotropy of β-particle fluences was examined to clarify the possible reason of such discrepancy.