![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
Summary
A homogeneous blood-thorium sulphate mixture has been used as a source of polonium-216 alpha-particle activity in two determinations of the half-life of this nuclide. The first method consisted of scintillation counting, by means of a scaler and six electro-mechanical registers, of the alpha-particle pairs produced by the decay of polonium-216 subsequent to that of its precursor, thoron-220. A more accurate result was provided by pulse-counting with a multi-channel analyser. Results are compared with those of three earlier experiments. The weighted mean of our two values for the half-life of polonium-216 (0,155 plusmn 0,004 seconds) is in better agreement with the result of Ward (1942) than with the determination by Diamond & Gindler (1963).