Standardization of Sm-153 solution by absolute methods

• Counting efficiency of 153Sm was calculated with simplified spectrum.
• Consistency of 153Sm standardization by two absolute methods was obtained.
• Uncertainty of measurement of 0.7% by the C/N method was evaluated.
• Half-life of 153Sm of (1.92895±0.00016) days was determined.

Standardization of 153Sm by 4π(LS)-γ coincidence and anticoincidence counting and the CIEMAT/NIST method in three LS-counters is presented. This short half-life radionuclide is applied in tumor therapy and bone pain palliation. A simplified disintegration scheme of 153Sm was applied in the calculation of the counting efficiency. Standard uncertainties of 0.4% for the 153Sm measurements by the 4π(LS)-γ coincidence and anticoincidence techniques and 0.7% by the C/N method were evaluated, respectively. An agreement of the standardization results by both methods within the respective uncertainties was obtained. The half-life of 153Sm of (1.92895±0.00024) days was determined during one month of measurements and correction for europium isotope impurities by the C/N method in the TriCarb 2910 LS-counter.