Curium is a synthetic chemical element; it has symbol Cm and atomic number 96. This transuranic actinide element was named after eminent scientists Marie and Pierre Curie, both known for their research on radioactivity. Curium was first intentionally made by the team of Glenn T. Seaborg, Ralph A. James, and Albert Ghiorso in 1944, using the cyclotron at Berkeley. They bombarded the newly discovered element plutonium with alpha particles. This was then sent to the Metallurgical Laboratory at University of Chicago where a tiny sample of curium was eventually separated and identified. The discovery was kept secret until after the end of World War II. The news was released to the public in November 1947. Most curium is produced by bombarding uranium or plutonium with neutrons in nuclear reactors – one tonne of spent nuclear fuel contains ~20 grams of curium.
The 60-inch (150 cm) cyclotron at the Lawrence Radiation Laboratory, University of California, Berkeley, in August 1939.
Several isotopes of curium were detected in the fallout from the Ivy Mike nuclear test.
Glenn Theodore Seaborg was an American chemist whose involvement in the synthesis, discovery and investigation of ten transuranium elements earned him a share of the 1951 Nobel Prize in Chemistry. His work in this area also led to his development of the actinide concept and the arrangement of the actinide series in the periodic table of the elements.
Seaborg (second from left) during Operation Plumbbob
From left to right: Chairman Seaborg, President Kennedy, Secretary McNamara on March 23, 1962. By this point, McNamara and Seaborg had been discussing the AEC's studies on the ecological effects of nuclear war and "clean" weapon alternatives. (Courtesy: National Security Archive, Original: National Archives)