Evaluating the intensity of the 803-keV γ ray of 210Po using a 4παβ(LS)-γ(HPGe) measurement system.

The absolute intensity for the 803-keV γ ray of 210Po was evaluated by α-γ coincidence technique. A liquid sample with a known amount of 210Po embedded in scintillation fluid was measured in a coincidence-based system that comprises a Liquid Scintillator (LS) detector and a High-Purity Germanium (HPGe) detector. A photo-reflector assembly that contains the 210Po sample provides 100% efficiency for detecting the α particles. The combination between the HPGe and the LS detectors allows to reject non-coincident α-γ events while maintaining high resolution γ spectroscopy. Consequently, the faint 803-keV photopeak from 210Po could be observed in a background-free environment, and its intensity could be evaluated with good accuracy. Sample measurements were carried out over nine months to gather statistics and verify the reliability of the experimental procedure. The absolute intensity of the 803-keV line was found to be (1.22 ± 0.03) × 10−5, in excellent agreement with the adopted value in a recent data compilation and consistent with previous experimental works. • The intensity of the 803-keV γ-ray emitted from 210Po was evaluated using a α-γ measurement system. • Result is in very good agreement with values from previous works. • Measurement uncertainty is competitive with other more traditional methods. • The method may be applicable to other low-intensity α-γ emitters. [ABSTRACT FROM AUTHOR]