Activity standardisation of ²²⁶Ra by 4πα liquid scintillation counting method

Area of Science:

• Nuclear physics
• Radiochemistry
• Analytical chemistry

Background:

• Accurate quantification of radionuclides is crucial for various applications, including environmental monitoring and nuclear medicine.
• Radium-226 ((226)Ra) is a significant radioisotope with a long half-life, posing potential health risks.
• Traditional measurement methods can be affected by the presence of short-lived daughter products, complicating activity determination.

Purpose of the Study:

• To develop and validate a precise method for determining the activity of radium-226 ((226)Ra) in solution.
• To minimize interference from transient radioactive equilibrium with radon and its progeny.
• To achieve a high level of accuracy and low uncertainty in (226)Ra activity measurements.

Main Methods:

• Utilized 4π liquid scintillation counting (LSC) for high detection efficiency.
• Employed solvent extraction to effectively remove radon-222 ((222)Rn) and its daughter nuclides immediately prior to LSC.
• Applied corrections for minor radium loss and ingrowth of (222)Rn and (218)Po after separation.

Main Results:

• Achieved near-unity detection efficiency for radium decay events.
• Demonstrated effective removal of radon and its daughter products, simplifying the activity calculation.
• Reported a combined relative standard uncertainty of less than 0.34% for the (226)Ra activity determination.

Conclusions:

• The developed 4π LSC method with solvent extraction is highly accurate for measuring (226)Ra activity.
• This technique minimizes errors associated with transient radioactive equilibrium, providing reliable results.
• The low uncertainty achieved makes this method suitable for demanding applications requiring precise radionuclide quantification.