Alternative radiochemical heavy ion activation methods for the production and separation of thallium radionuclides.

Heavy ion activation of natural gold foil with a 7Li beam results in the formation of carrier-free 199-201Pb radionuclides along with their corresponding decay products, 199-201Tl, in the matrix. At 49 MeV projectile energy, the production of 199Tl through its precursor 199Pb is maximal, while that of other. thallium radionuclides is minimal. Another way for the direct production of carrier-free thallium radionuclides is to irradiate natural platinum foil with a 7Li beam; on this case, production of 199Tl is maximal at 43 MeV projectile energy. The carrier-free thallium radionuclides have been separated from the bulk target matrix gold and platinum by liquid-liquid extraction using trioctylamine as a liquid anion exchanger.