Standardization of 169Yb by the 4pibeta-gamma method

Area of Science:

• Nuclear Physics
• Metrology
• Radiochemistry

Background:

• Accurate standardization of radionuclides is crucial for various applications, including medical imaging and research.
• International comparisons ensure consistency and traceability of measurement results across different laboratories.
• Ytterbium-169 (169Yb) is a radionuclide with specific decay properties requiring careful consideration during standardization.

Purpose of the Study:

• To standardize the activity concentration of two 169Yb solutions within an EUROMET international comparison.
• To validate the 'beta-efficiency extrapolation' variant of the coincidence method for 169Yb standardization.
• To provide accurate traceable activity concentration values for both weak and strong 169Yb solutions.

Main Methods:

• Utilized a 4pi beta-gamma coincidence counting system.
• Employed the 'beta-efficiency extrapolation' method for standardization.
• Selected a resolution time of 5.1 microseconds and a gamma threshold of 150 keV, accounting for 169Tm metastable states.
• Applied a second-degree extrapolation graph for data analysis.

Main Results:

• Standardized the weak 169Yb solution to an activity concentration of 1.18 MBq g(-1) on November 15, 1997, 12:00 UT.
• Achieved a combined uncertainty of 0.9% for the weak solution standardization.
• Calculated the activity concentration for the strong solution as 11.989 MBq g(-1) with a combined uncertainty of 0.92%.

Conclusions:

• The 'beta-efficiency extrapolation' method is effective for standardizing 169Yb activity concentrations.
• The results contribute to the international traceability of 169Yb measurements.
• Accurate standardization of 169Yb is achievable with appropriate coincidence counting techniques and parameter selection.