Equilibrium evaporation of trace polonium from liquid lead-bismuth eutectic at high temperature

The evaporation of Po from its dilute solution in liquid lead–bismuth eutectic (LBE) was determined between 700 and 1000 C in Ar/5%H2 by the transpiration method. Concurrent measurements of the evaporation of LBE could be well reproduced by calculations using literature data, confirming conditions of equilibrium and convective vapor transport in our transpiration method experiments. This allowed to model the Po evaporation data and extract accurate temperature correlations for the Henry constant for Po dissolved in LBE at two different Po concentrations. Extrapolations of the new correlations were in excellent agreement with existing data at lower temperature.