Ralph Arthur James (23 September 1920 in Salt Lake City, Utah[1] – 24 February 1973 in Alamo, California) was an American chemist at the University of Chicago who co-discovered the elements curium (1944) and americium (1944–1945). Later he worked at UCLA and for the Lawrence Livermore laboratory in California.
Ralph Arthur James | |
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Born | Salt Lake City, Utah, US | September 23, 1920
Died | February 24, 1973 | (aged 52)
Nationality | American |
Known for | Co-discovery of curium, americium |
Scientific career | |
Fields | Chemistry |
He also worked on niobium and nuclear spectroscopy.[2]
James was part of the Laboratory of Metallurgy, University of Chicago, the team directed by Glenn T. Seaborg. The laboratory had large amounts of plutonium (discovered in 1940–41) that was being produced at the Hanford Site to make nuclear weapons. This allowed them to discover two new elements, although the difficulties for study and isolation were great.
In 1944, Seaborg decided to extend the search to heavier elements, and instructed chemists Ralph A. James and Leon O. Morgan to send samples of irradiated plutonium to Albert Ghiorso for analysis. By identifying characteristics of emitted alpha particles they found the new elements.
Curium (atomic number 96) was discovered in 1944 by Glenn T. Seaborg, Ralph A. James and Albert Ghiorso during World War II in the Chicago Metallurgical Laboratory, as part of the Manhattan Project, by bombarding plutonium with helium ions.[3][4] It was named in honor of Pierre Curie and Marie Sklodowska Curie.
Similarly, americium (atomic number 95) was discovered in 1944–45 by Glenn T. Seaborg, Ralph A. James, Leon O. Morgan and Albert Ghiorso, working as part of the Manhattan Project. By bombarding plutonium neutrons in the 60-inch cyclotron at the University of California, Berkeley.[5][6] It was named after the continents of America, and because it is a homologous element of europium (atomic number 63), positioned right above it on periodic charts.