Americium-241
Small button containing 241AmO2 from a smoke alarm | |
| General | |
|---|---|
| Symbol | 241Am |
| Names | americium-241 |
| Protons (Z) | 95 |
| Neutrons (N) | 146 |
| Nuclide data | |
| Natural abundance | 0 (synthetic) |
| Half-life (t1/2) | 432.6±0.6 years |
| Isotope mass | 241.0568273(12) Da |
| Spin | 5/2− |
| Excess energy | 52934.3±1.1 keV |
| Nuclear binding energy | 7543.2795(46) keV |
| Parent isotopes | 241Pu (β−) 241Cm (EC) 245Bk (α) |
| Decay products | 237Np |
| Decay modes | |
| Decay mode | Decay energy (MeV) |
| α-decay (alpha) | 5.486 |
| γ-emission (gamma) | 0.0595409 |
| Isotopes of americium Complete table of nuclides | |
Americium-241 (241Am, Am-241) is an isotope of americium. Like all isotopes of americium, it is radioactive, with a half-life of 432.6 years. 241Am is the most common isotope of americium as well as the most prevalent americium isotope in radioactive waste. It is used in ionization-type smoke detectors and is a potential fuel for long-lifetime radioisotope thermoelectric generators (RTGs). Its common parent nuclides are β− from 241Pu, EC from 241Cm, and α from 245Bk. 241Am is fissile. The critical mass of a bare sphere is 57.6–75.6 kilograms (127.0–166.7 lb) and a sphere diameter of 19–21 centimetres (7.5–8.3 in). Americium-241 has a specific activity of 3.43 Ci/g (126.91 GBq/g). It is commonly found in the form of americium-241 dioxide (241AmO2). The presence of 241Am in plutonium is determined by the original concentration of plutonium-241 (which decays to it) and its age. Older samples of plutonium containing 241Pu build up 241Am may require chemical removable of americium-241 (e.g., during reworking of plutonium's pits).