Californium

Californium, chemical element, symbol Cf; for physical constants see Periodic Table. Californium is a radioactive element that does not occur naturally. It was produced in 1950 by Glenn Seaborg and others, by bombarding curium-242 with helium ions in a cyclotron. Californium is metallic, a member of the actinide series. It is produced in nuclear reactors and is a source of neutrons.