Americium

Americium is a synthetic, radioactive transuranic actinide metal. Only tiny, unconfirmed traces may occur naturally in uranium minerals; most americium is made in nuclear reactors by neutron irradiation of uranium or plutonium and then separated from other radioactive materials. Americium-241, a long-lived isotope, is used in ionization smoke detectors and, combined with beryllium, in neutron sources for scientific and industrial measurements. Its gamma rays are also used to analyze materials and calibrate instruments. These applications depend on particular isotopes or compounds, not ordinary americium metal.