Assessing the ~(210)At impurity in the production of ~(211)At for radiotherapy by ~(210)Po analysis via isotope dilution alpha spectrometry

摘要

A method for assessing the impurity ~(210)At in cyclotron-produced ~(211)At via isotope dilution alpha spectrometry is presented. Theactivity of ~(210)At is quantified by measuring the activity of daughter nuclide ~(210)Po. Counting sources are prepared by spontaneous deposition of Po on a silver disc. Activity of ~(210)At (at the time of ~(210)Po maximum activity) is found to be 83.5 +- 9.0 Bq, corresponding to an atom ratio (~(210)At:~(211)At at the time of distillation) of 0.010+-0.007percent (k velence 2). The method produces high-quality alpha spectra, with baseline alpha-peak resolution and chemical yields of greater than 85percent.