Why is AM 241 used in smoke alarms?
Why is AM 241 used in smoke alarms?
Ionization smoke detectors use americium as a source of alpha particles. Alpha particles from the americium source ionize air molecules. This makes some particles positively charged and some negatively charged. Because of this shielding, the smoke detector poses no radiation health risk when they are properly handled.
What does AM 241 decay into?
The amount of 241Am declines slowly as it decays into neptunium-237, a different transuranic element with a much longer half-life (about 2.14 million years).
What happens when americium-241 undergoes alpha decay?
An americium-241 atom will spontaneously throw off an alpha particle. An alpha particle is made up of two protons and two neutrons bound together, which is the equivalent of a helium-4 nucleus. In the process of emitting the alpha particle, the americium-241 atom becomes a neptunium-237 atom.
How is AM 241 made?
Americium-241 is produced in nuclear power plants during activation of 239Pu and 240Pu by neutrons, which is followed by beta decay of 241Pu (T1/2 = 14.35 years). This means that also in burned-up fuel 241Am is produced by decay of 241Pu a long time after the fuel is removed from a nuclear reactor.
How is AM 241 produced?
Americium is produced when plutonium absorbs neutrons in nuclear reactors or during nuclear weapons tests. Americium-241 is the most common form of Americium.
How is americium-241 created?
Americium-241 is formed in the environment by the decay of plutonium contamination from nuclear weapons production and testing. Americium-241 is an unstable isotope. As americium decays, it releases radiation and forms “daughter” elements.
How is americium-241 produced?
Americium (chemical symbol Am) is a man-made radioactive metal that is solid under normal conditions. Americium is produced when plutonium absorbs neutrons in nuclear reactors or during nuclear weapons tests. Americium-241 is the most common form of Americium.
What isotope remains after the α decay of americium-241 in smoke detectors?
neptunium-237
The isotope of americium used in smoke detectors is americium-241, which decays by α emission to neptunium-237 with a half-life of 432.2 years.
What happens if you touch americium?
Exposure to extremely high levels of americium, as has been reported in some animal studies, has resulted in damage to organs such as the lungs, liver, kidneys, and thyroid. It is rare, however, that a person would be exposed to amounts of americium large enough to cause harmful effects in these organs.
How does americium 241 work in a smoke detector?
A common type is ionization smoke detector which contains a small amount of americium-241 as an oxide. Americium-241 emits alpha particles and low energy gamma rays. The alpha particles emitted by the Am-241 collide with the oxygen and nitrogen in air within the detector’s ionization chamber to produce charged particles (ions).
Which is the daughter nuclide of americium 241?
It is emitted as a decay product of many radionuclides predominantly of atomic number greater than 82. For example, the radionuclide americium-241 ( 241 Am) decays by alpha-particle emission to yield the daughter nuclide 237 Np according to the following equation:
Where can you find americium-241 in the environment?
Exposure to any significant amount of Am-241 is unlikely under normal circumstances. Small amounts of it are found in the soil, plants and water from nuclear weapons testing. Some smoke detectors contain very small amounts of Am-241.
What can 241Am be used for in a nuclear reactor?
The obtained 241Am can be used for generating heavier americium isotopes by further neutron capture inside a nuclear reactor. In a light water reactor (LWR), 79% of 241Am converts to 242Am and 10% to its nuclear isomer 242mAm:
