Purification of Uranium Metal using the Solid State Electrotransport Method under Ultrahigh Vacuum

A uranium ingot was successfully purified using the solid state electrotransport (SSE) method. The concentration of impurities was dramatically reduced after the SSE treatment. In particular, magnetic transition metals such as Fe and Cu were removed almost completely. Impurities with high vapor pressure such as Mn and Zn were evaporated. The mechanism of the impurity-reduction was qualitatively explained by three effects: sweeping out by the flow of the electrical current, diffusion and evaporation. It is very important to hold the uranium ingot at a high temperature just below the melting point.