Gamma ray

[taixyz1992]

Gamma radiation, also known as gamma rays (denoted as γ), is electromagnetic radiation of high frequency (very short wavelength). They are produced by sub-atomic particle interactions such as electron-positron annihilation, neutral pion decay, radioactive decay, fusion, fission or inverse Compton scattering in astrophysical processes. Gamma rays typically have frequencies above 1019 Hz, and therefore have energies above 100 keV and wavelength less than 10 picometers, often smaller than an atom. Gamma rays from radioactive decay commonly have energies of a few hundred keV, and are almost always less than 10 MeV in energy.

Because they are a form of ionizing radiation, gamma rays can cause serious damage when absorbed by living tissue, and are therefore a health hazard.

Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900, while studying radiation emitted from radium.[1] Alpha and beta "rays" had already been separated and named by the work of Ernest Rutherford in 1899, and in 1903 Rutherford named Villard's distinct new radiation "gamma rays."

Oakley
jeux de poker a telecharger