Method of Polonium Source Preparation Using Tellurium Microprecipitation for Alpha Spectrometry

A thin-layer source for the counting of polonium isotopes by alpha spectrometry can be rapidly prepared using microprecipitation with tellurium. Polonium was first coprecipitated with the reduction of tellurium by stannous chloride, followed by microfiltration onto a membrane filter for counting. This microprecipitation method is faster, cheaper, and more convenient than the traditional spontaneous deposition method, with an excellent Po recovery (>90%) under optimal conditions. The influences of several experimental parameters, including Te(IV) quantity, reaction time, and HCl molarity, were examined to determine the optimal conditions for Te microprecipitation. The decontamination factors of potential interferences from various radionuclides (Ra, Th, U, Pu, Am) for the counting of long-lived polonium isotopes (²⁰⁸Po, ²⁰⁹Po, and ²¹⁰Po) were also evaluated, and the results confirmed a good selectivity on polonium by this microprecipitation method. Due to its strong resistance to high acidity up to 12 M HCl, the method would be particularly suitable for rapid determination of ²¹⁰Po in acid leaching solution of solid samples.