High purification of metallic uranium by solid-phase electrolytic method

We succeeded to purify metallic uranium by a solid phase electrolytic method (or an electro·transport method). In this method, a large electric current flows through the metallic uranium bar under the conditions of ultra-high vacuum. When a metallic uranium is heated at about the melting point, impurities move and then a part of uranium is purified. Various kinds of impurities are classified as following: Mn, Cu and Zn are removed less than the detection limit, Fe, Ni and V diffused into near anode and Mg, Al and Cr diffused into both sides. The concentration of iron decreased less than 3%. The residual resistance rate of URu2Si2, single crystal, is changed from 32 to 255 by purification. (S.Y.)