Americium

Americium is a transuranic radioactive chemical element. Most americium is produced by bombarding uranium or plutonium with neutrons in nuclear reactors – one tonne of spent nuclear fuel contains about 100 grams of americium. It is widely used in commercial ionization chamber smoke detectors, as well as in neutron sources and industrial gauges. Several unusual applications, such as a nuclear battery or fuel for space ships with nuclear propulsion, are also known.

Americium is a relatively soft radioactive metal with silvery appearance. The crystal lattice of solid americium and its compounds contains intrinsic defects, which are induced by self-irradiation with alpha particles and accumulate with time; this results in a drift of some material properties.