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Two determinations of the 223Ra half-life



Denis E. Bergeron, Ryan P. Fitzgerald


Ra-223 is an alpha-emitter that is being used as a bone-seeking radiotherapeutic agent. The relatively large uncertainty on its half-life (0.26 %, Bé et al., 2011) is an impediment to precision activity assays. We have performed two series of measurements using an ionization chamber (IC) and a NaI(Tl) well counter (γ-wc) to determine new, precise values for the 223Ra half-life. We have endeavored to realistically assess the uncertainties on the derived half-lives, looking beyond the fit uncertainties to identify uncertainty components acting on multiple timescales. We recovered respective values of 11.447(6) d and 11.445(13) d from the IC and γ-wc measurements.
Applied Radiation and Isotopes


Ra-223, half-life, decay constant, ionization chamber, gamma well counter


Bergeron, D. and Fitzgerald, R. (2015), Two determinations of the 223Ra half-life, Applied Radiation and Isotopes, [online], (Accessed May 25, 2024)


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Created May 1, 2015, Updated November 10, 2018