Arthur choice

Arthur choice

Arthur C. Wahl (born September 8, 1917 in Des Moines , Iowa , † March 6, 2006 in Santa Fe ) was an American chemist who dealt with nuclear chemistry and is one of the discoverers of plutonium .

Arthur Wahl studied at Iowa State University with a bachelor's degree in chemistry in 1939. He was then a student of Glenn Theodore Seaborg and Joseph W. Kennedy at the University of California, Berkeley . Together with Edwin McMillan, he headed a working group that produced the element plutonium (atomic number 94) for the first time in February 1941 . Wahl first isolated the neptunium (atomic number 93) obtained from irradiation of uranium-238 with deuterium and observed the development of a long-lived alpha decay, typical of plutonium, which was formed as an isotope with mass number 238 from neptunium through beta decay. In order to assign the radiation to a new element, the similar decay of thorium had to be ruled out. Wahl tried to achieve this by generating a higher oxidation state than that of thorium with oxidation state 4. He did so at midnight on February 24, 1941, working alone in Room 307 of Gilman Hall, Berkeley. He then isolated plutonium of mass number 239 with Kennedy, Seaborg and Emilio Segrè . They irradiated 1.2 kilograms of uranium oxide with neutrons for two days and recovered 0.5 micrograms of plutonium-239 (today as Sample B in the Smithsonian Institution). They found that it was fissionable by both fast and slow neutrons. He received his doctorate for this work in 1942.

In the Manhattan Project , from 1943 to 1946 in Los Alamos he headed the group for research into the chemistry of plutonium and its pure representation.

After the war, Arthur Holly Compton brought Joseph W. Kennedy to the chair of chemistry at Washington University , which made it a condition that he election and four other members (Lindsay Helmholz, David Lipkin, Herb Potratz, Sam Weissman) of the chemistry group from Los Alamos could bring. He became a professor there and mainly dealt with the collection and tabulation of nuclear fission data and oxidation-reduction reactions. He taught inorganic chemistry, including teaching the beginner laboratory courses. From 1991 he conducted research in Los Alamos again. He published his last compilation of nuclear fission data in 2005. He died of pneumonia and complications from Parkinson's.

literature

• Lee Sobotka, Alfred M. Holtzer, Gerhart Friedlander, Demetrios G. Sarantites, Samuel I. Weissman: Obituary of Arthur C. Wahl, Physics Today, July 2006, online