Scintillation β-spectrometer with enhanced sensitivity

The design of a high-sensitive scintillation beta-spectrometer applied for measuring the content of (90)Sr in environmental samples against the background (40)K and (137)Cs is described. The spectrometer includes a plastic detector with developed surface, to be simultaneously used as a sample container. The content of (90)Sr is determined having a beta-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.