PRODUCTION OF TL-201 AND PB-203 VIA PROTON-INDUCED NUCLEAR-REACTIONS ON NATURAL THALLIUM

Excitation functions for the formation of 204mPb, 203Pb, 202mPb, 201Pb, 200Pb, 199Pb, 202Tl and 201Tl in the interactions of natural thallium with protons have been measured by the stacked-foil technique within the proton energy range of 8-45 MeV. For the production of both the medically important radioisotopes 201Tl and 203Pb in a high radionuclidic purity, the optimum incident proton energy was found to be 28 MeV and, theoretically, thick target yields of 0.50 mCi μAh-1 and 3.5 mCi μAh-1, respectively, were achieved. The whole-body radiation dose due to the 200Tl contaminant is five times higher than that due to 201Tl. A target system for the production of 201Tl and 203Pb in a high current compact cyclotron is described. Some observations on the radiochemical separation of lead and thallium are discussed. A procedure for the carrier-free separation of 203Pb and 201Tl activities, employing anion-exchange chromatography, as well as methods for the analytical quality control of the final products are described. © 1979.