Charged-particle activation analysis for trace impurities in water

A charged particle activation technique has been developed to analyze for trace impurities in the ppm range or less in water. Water samples are evaporated onto a tantalum foil and activated in a 15 MeV proton beam in the present work. The gamma ray spectrum from the activated sample is analyzed to quantitatively determine simultaneously trace amounts of boron, bromine, sodium, cadmium, chromium, selenium, and nitrogen. Total irradiation and counting time is less than two minutes. Beam currents are ≲ 1 μa.