Precise measurements of the absolute γ-ray emission probabilities of 223Ra and decay progeny in equilibrium. (August 2015)

• Record Type: Journal Article
• Authors: Collins, S.M.; Pearce, A.K.; Regan, P.H.; Keightley, J.D.
• Is Part Of: Applied radiation and isotopes. Volume 102(2015:Aug.)
• Page Start: 15
• Page End: 28
• Publication Date: 2015-08
• Subjects: Nuclear data -- 223Ra -- 219Rn -- 215Po -- 211Pb -- 207Tl -- Gamma-ray emission probabilities -- Gamma-ray spectrometry -- Correlation coefficients -- Radioactivity; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2015.04.008
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: Precise measurements of the absolute γ -ray emission probabilities have been made of radiochemically pure solutions of 223 Ra in equilibrium with its decay progeny, which had been previously standardised by 4 π (liquid scintillation)- γ digital coincidence counting techniques. Two high-purity germanium γ -ray spectrometers were used which had been accurately calibrated using a suite of primary and secondary radioactive standards. Comparison of the activity concentration determined by the primary technique against γ -ray spectrometry measurements using the nuclear data evaluations of the Decay Data Evaluation Project exhibited a range of ~18% in the most intense γ -ray emissions (>1% probability) of the 223 Ra decay series. Absolute γ -ray emission probabilities and standard uncertainties have been determined for the decay of 223 Ra, 219 Rn, 215 Po, 211 Pb, 211 Bi and 207 Tl in equilibrium. The standard uncertainties of the measured γ -ray emission probabilities quoted in this work show a significant improvement over previously reported γ -ray emission probabilities. Correlation coefficients for pairs of the measured γ -ray emission probabilities from the decays of the radionuclides 223 Ra, 219 Rn and 211 Pb have been determined and are presented. The α -transition probabilities of the 223 Ra have been deduced from P ( γ +ce) balance using the γ -ray emission probabilities determined in this work with some agreement observed with the published experimental values of the α -emission probabilities. Highlights: Discrepancies found within currently published γ -ray emission probabilities. Absolute γ -ray emission probabilities of decay series in equilibrium determined. Significant improvement in precision of measured values. Closer agreement between deduced and experimental α transition probabilities. Correlation coefficients presented for γ -emissions of 223 Ra, 219 Rn and 211 Pb.