Discovery of plutonium

Plutonium was first produced in late 1940 and identified in early 1941 by Glenn Seaborg, Edwin McMillan, Joseph Kennedy and Arthur Wahl at the University of California, Berkeley. They created it by bombarding uranium with deuterons in a cyclotron, which produced an isotope that decayed into one with different chemical properties. Because of wartime secrecy, the discovery was not made public until 1946. The element was named after Pluto, following neptunium, which in turn followed uranium, as the planets Pluto and Neptune followed Uranus. During the Manhattan Project plutonium was produced in reactors, and it fuelled the Trinity test in July 1945 and the bomb dropped on Nagasaki the following month. It is now also used in nuclear reactors and as a power source in some space probes.

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