Scintillation β-spectrometer with enhanced sensitivity

The design of a high-sensitive scintillation β-spectrometer applied for measuring the content of 90Sr in environmental samples against the background 40K and 137Cs is described. The spectrometer includes a plastic detector with developed surface, to be simultaneously used as a sample container. The content of 90Sr is determined having a β-spectrum region of interest 1311–2282 keV. The minimum detectable specific activity of the spectrometer is 3.5 Bq/kg for solid granular samples with a mass of 1000 g and a measuring time of 2 h.