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Primary standardization of Ra-224 activity by liquid scintillation counting



Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Brian E. Zimmerman, Lizbeth Laureano-Perez, Ronald Colle, Leticia S. Pibida, Elisa Napoli


A standard for 224Ra activity has been developed, based on triple-to-double coincidence ratio (TDCR) liquid scintillation (LS) counting. The standard was confirmed by efficiency tracing and 4παβ(LS)-γ(NaI(Tl)) anticoincidence counting, as well as by 4πγ ionization chamber and NaI(Tl) measurements. Secondary standard ionization chambers were calibrated with an expanded uncertainty of 0.57 % (k = 2). Calibration settings were also determined for a 5 mL flame- sealed ampoule on several commercial reentrant ionization chambers (dose calibrators).
Applied Radiation and Isotopes


TDCR, liquid scintillation, anticoincidence counting, efficiency tracing, alpha therapy, activity calibration


Bergeron, D. , Cessna, J. , Fitzgerald, R. , Zimmerman, B. , Laureano-Perez, L. , Colle, R. , Pibida, L. and Napoli, E. (2019), Primary standardization of Ra-224 activity by liquid scintillation counting, Applied Radiation and Isotopes, [online], (Accessed June 20, 2024)


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Created October 11, 2019, Updated March 12, 2020