Abstract
Carrier-free 202Tl was thermally separated from proton-irradiated natHgO . Pressed natHgO targets were irradiated with ≈ 26 MeV protons at the IP2 beamline of the high-intensity proton accelerator facility at the Paul Scherrer Institute. The well-known thermal decomposition of HgO at > 470 ∘ C and the strong adsorption of Tl on a Ta surface allowed for a simple and quantitative gas-phase separation of carrier-free Tl from bulk amounts of HgO target material between 550 and 670 ∘ °C. The separation efficiency was verified by γ -spectroscopy via the main γ -emissions of 202Tl and co-produced 203Hg . This method generally provides a fast and reliable preparation of carrier-free, neutron-deficient Tl radioisotopes (e.g., medically relevant 201Tl ) from a proton-irradiated natHgO matrix.