What isotopes are used in smoke detectors

How are isotopes used to make smoke alarms?

Americium-241 is the isotope used in smoke detectors. It decays by I+ emission to neptunium-237 and has a half-life that is 432.2 years. The smoke detector contains close to 100% of americium when it was new. About 4.7% of the atoms of americium will have decomposed to neptunium after 30 years.

What is the danger of americium 241? Hazards. Americium - 241 presents the same hazards as other americium Isotopes. It is extremely toxic and radioactive. Although I+ particles can be stopped with a piece of paper, ingestion of I+ emitters poses serious health risks.

Also, why is americium used for smoke detectors?

Alpha particles are produced by ionization smoke detectors using americium. The americium source emits alpha particles that ionize air molecules. Some particles are positively charged while others are negatively charged. When the constant flow is interrupted by smoke, the smoke alarm will sound.

Are there any uranium-containing smoke detectors?

A majority of americium is made from uranium and plutonium bombarded by neutrons in nuclear nuclear reactors. One tonne of spent nuclear fuel contains approximately 100 grams of americium. It is used extensively in industrial gauges and neutron sources, as well as commercial ionization chamber smoke detectors.