Polonium evaporation from liquid lead–bismuth eutectic with different oxygen content

Accurate knowledge of polonium evaporation from lead–bismuth eutectic (LBE) is crucial for the design of accelerator driven nuclear systems in which LBE is used as target material or coolant. In this work we investigated the relation between the oxygen content and its distribution in liquid LBE samples and polonium evaporation from these samples at 400 °C. A fraction of the polonium was rapidly released, and we found a correlation between the amount of this fast-released polonium and the amount of oxygen concentrated in an oxide layer on top of the LBE sample. A qualitative model describing the polonium evaporation behavior in relation to oxygen content and distribution in polonium-doped LBE samples is outlined.