Measurement of absolute γ-ray emission probabilities in the decay of 227Ac in equilibrium with its progeny

• Published in: Applied radiation and isotopes 2019-02, Vol.144, p.34-46
• Main Authors: Marouli, M., Lutter, G., Pommé, S., Van Ammel, R., Hult, M., Pierre, S., Dryák, P., Carconi, P., Fazio, A., Bruchertseifer, F., Morgenstern, A.
• Format: Article
• Language: English
• Subjects: 223Ra; 227Ac; 227Th; Decay data; γ-ray intensities; γ-ray spectrometry
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2018.08.023

The emission probabilities of γ rays produced in the 227Ac decay series were determined by high-resolution γ-ray spectrometry of sources with standardised activity. The sources were prepared quantitatively on glass discs by drop deposition of a solution with 227Ac in radioactive equilibrium with its daughter nuclides. Their activity was measured by a primary standardisation technique based on alpha-particle counting at a defined low solid angle. Four laboratories performed γ-ray spectrometry and derived absolute γ-ray intensities. Mean values were calculated and compared with literature data and the currently recommended evaluated data. New values on certain γ-ray emission probabilities are proposed. •Measured gamma-ray emission probabilities in 227Ac decay series.•Mean values taken from 4 laboratories.•Source activity determined by primary standardisation.•Results reported for 87 γ-ray lines.•Generally in good agreement with literature values.