A novel method for the preparation of large-area 90Sr/90Y sources for the calibration of hand contamination monitors

This paper describes a method for the preparation of large-area 90Sr/90Y polymer film sources for the calibration of hand contamination monitors. The process consists of solvent extraction of predictable quantity of 90Sr into an organic solvent containing di-tert-butyl-cyclohexano-18-crown-6 (DCH18C6), formation of a polymeric solution of poly(methyl methacrylate) (PMMA), pouring the 90Sr-embedded polymer solution over a surface of a defined area followed by evaporation to create a thin film and peeling-off of the radioactive PMMA film. Quality control tests of the radioactive films were carried out to ensure nonleachability, uniform distribution of activity and stability. Sources having 5 kBq±428 Bq were prepared using this method and routinely used for calibration of contamination monitors.