Ionizing radiation

Ionizing radiation is generated through nuclear reactions, either artificial or natural, by very high temperature (e.g. plasma discharge or the corona of the Sun), via production of high energy particles in particle accelerators, or due to acceleration of charged particles by the electromagnetic fields produced by natural processes, from lightning to supernova explosions.

When ionizing radiation is emitted by or absorbed by an atom, it can liberate an atomic particle (typically an electron, proton, or neutron, but sometimes an entire nucleus) from the atom. Such an event can alter chemical bonds and produce ions, usually in ion-pairs, that are especially chemically reactive. This greatly magnifies the chemical and biological damage per unit energy of radiation because chemical bonds will be broken in this process. If the atom were inside a crystal lattice in a solid phase, then a "hole" would exist where the original atom was.

Ionizing radiation includes both subatomic particles of matter moving at relativistic speeds and electromagnetic waves on the short wavelength end of the electromagnetic spectrum, which act like energetic particles. Common particles include alpha particles, beta particles, neutrons, and various other particles such as mesons that constitute cosmic rays. Electromagnetic waves are ionizing if their wavelength is short enough (and thus their energy high enough) that the photons can create ions by liberating electrons as described above. Gamma rays, X-rays, and the upper vacuum ultraviolet part of the ultraviolet spectrum are ionizing, while the lower ultraviolet, visible light (including laser light), infrared, microwaves and radio waves are considered non-ionizing radiation.

Wikipedia: The free encyclopedia [online]. 2014 [cit. 2014-01-23]. Source: http://www.en.wikipedia.org/

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Visualization: What is ionizing radiation?

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