Encyclopedia > Alpha rays

  Article Content

Alpha particle

Redirected from Alpha rays

Alpha particles or alpha rays are a form of particle radiation which are highly ionizing and have low penetration. They consist of two protons and two neutrons bound together into a particle that is identical to a helium nucleus, and can be written as He2+. In contrast to beta decay, Alpha decay is mediated by the strong nuclear force.

Alpha particles are emitted by radioactive nuclei such as uranium or radium in a process known as alpha decay. This sometimes leaves the nucleus in an excited state, with the emission of a gamma ray removing the excess energy.

Alpha rays are easily absorbed by materials and can travel only a few centimeters in air. They can be absorbed by tissue paper or the outer layers of human skin and so are not generally dangerous to life unless the source is ingested or inhaled. If Alpha radiation does enter the body, however, they are the most dangerous form of ionising radiation. They are the most strongly ionising, and with large enough doses can cause any or all of the symptoms of radiation poisoning.

See also: radioactivity, cosmic rays, nuclear physics, radioactive isotopes, radioactive decay



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
East Farmingdale, New York

... every 100 females age 18 and over, there are 100.6 males. The median income for a household in the town is $68,125, and the median income for a family is $71,726. Males ...

 
 
 
This page was created in 36.2 ms