Ionization (redirected from ionization density)

ionization: see ion.

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ionization

Process by which electrically neutral atoms or molecules are converted to electrically charged atoms or molecules (ions) by the removal or addition of negatively charged electrons. It is one of the principal ways in which radiation transfers energy to matter, and hence of detecting radiation. In general, ionization occurs whenever sufficiently energetic charged particles or radiant energy travels through gases, liquids, or solids. A certain minimal level of ionization is present in the earth's atmosphere because of continuous absorption of cosmic rays from space and ultraviolet radiation from the sun.

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Ionization

The process by which an electron is removed from an atom, molecule, or ion. It is of basic importance to electrical conduction in gases and liquids. In the simplest case, ionization may be thought of as a transition between an initial state consisting of a neutral atom and a final state consisting of a positive ion and a free electron. In more complicated cases, a molecule may be converted to a heavy positive ion and a heavy negative ion which are separated.