Californium, named after the University of California, is a synthetic radioactive metal that does not occur naturally. It is a powerful neutron emitter, which makes it useful as a startup neutron source for certain nuclear reactors.
Chemical properties:
Californium is a silvery-white actinide metal, solid at room temperature, with the atomic symbol Cf, atomic number 98, and atomic weight 251. It has a valence of +2 or +3, a melting point of about 900 ± 30 °C (1,650 ± 50 °F), and an estimated boiling point of 1,743 K (1,470 °C; 2,680 °F). The pure metal is malleable and easily cut with a knife.
What are the uses of Californium?
It is used in portable metal detectors to identify gold and silver ores, detect water and oil layers in oil wells, and assess metal fatigue and stress in aeroplanes. Additionally, it has medical applications as a radiation source for brachytherapy.
Who created Californium?
Californium-245 was first produced in 1950 in California, USA, by researchers Stanley Thompson, Kenneth Street, Albert Ghiorso, and Glenn Seaborg. They bombarded curium-242 with alpha particles using the 60-inch cyclotron in Berkeley, California. Each nuclear reaction resulted in the creation of californium-245, which has a half-life of 44 minutes, along with a neutron emission.
In which country is Californium found?
Currently, only the United States and Russia can produce californium. In the U.S., californium is produced at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. In Russia, it is produced at the Research Institute of Atomic Reactors.
How much Californium is on Earth?
Californium is not naturally occurring or found in natural deposits anywhere on Earth. Only a few grams of Cf-252 are produced annually at two facilities in the USA and Russia.
Raw Material for Californium Production
The Californium manufacturing plant report states that curium-242 is the primary raw material used to produce Californium-252 through prolonged neutron irradiation in a nuclear reactor.
Who buys Californium?
Californium is a restricted radioactive substance bought in microgram quantities by scientific instrument makers. It can only be acquired under license from the Oak Ridge National Labs or Russian counterparts. In India, the sale and purchase of californium are prohibited.
What is the cost of Californium ?
Californium is rare and expensive, costing approximately $25 million (Rs.22 Cr) per gram. Producing even a few atoms of Californium requires large teams of highly trained scientists, contributing to its high price.
Why is Californium so expensive?
Californium does not occur naturally and must be synthesized in laboratories, where scientists can only produce small quantities at a time. After its initial discovery, it took scientists ten years to generate enough californium to weigh it. The total annual production at both research centers is just 0.5 grams.
Is Californium harmful to humans?
Californium is highly dangerous when introduced into the body. When it accumulates in skeletal tissue, it emits radiation that disrupts the formation of red blood cells. Additionally, californium-249 and californium-251 can cause external tissue damage due to their gamma ray emissions. The ionizing radiation emitted by californium can lead to cancer, particularly affecting bones and the liver.
