Californium was synthesised in 1950 at the University of California, Berkeley, by Stanley Thompson, Kenneth Street, Albert Ghiorso and Glenn Seaborg. They bombarded a tiny amount of curium with alpha particles in a cyclotron, and detected a few atoms of the new element with atomic number 98. It was named after the state and the university where it was produced, and it was announced in 1950. Californium is a radioactive metal and a strong source of neutrons, because one of its isotopes undergoes spontaneous fission. It is used to start up nuclear reactors, to detect explosives and gold in the ground, to analyse materials by neutron activation and, in some medical settings, to treat cancers. Only small quantities are made, by neutron irradiation in specialised reactors.
Before and after
- 1950Discovery of the Ishango bone
- from c. 1950s to 1970sDecolonisation of Africa
- c. 1950sInvention of Holter monitor
- c. 1950sRise of pop art
- 1950Discovery of californium
- 1950Origins of Formula One
- from 1950 to 1954McCarthyism
- 1950Fermi paradox
- 1950Publication of The Lion, the Witch, and the Wardrobe
More in Science & technology
- 1945Invention of computer
- 1964Discovery of rutherfordium
- 29 October 1969Invention of Internet
- 1984Discovery of hassium
- 15 January 2001Wikipedia
- 20 October 2004Creation of Ubuntu
The era
This moment belongs to the Contemporary world (1945 CE to today), the world since 1945. You can also browse everything in the 20th century.