Ionization

Ionization is the physical process of giving or taking away electrons from an atom. That makes the atom into an ion, because ions have electrical charge.

In the process of ionization, an electrically neutral atom becomes either positively or negatively charged. Some substances are easier to ionize than others. This depends on the ionization energy. Ionizing radiation is a common cause, but ionization can also be done by high temperature, radioactive decay, or other causes.

Ionization Media

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  The solar wind moving through the magnetosphere alters the movements of charged particles in the Earth's thermosphere or exosphere, and the resulting ionization of these particles causes them to emit light of varying colour, thus forming auroras near the polar regions.

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  Avalanche effect in an electric field created between two electrodes. The original ionization event liberates one electron, and each subsequent collision liberates a further electron, so two electrons emerge from each collision: the ionizing electron and the liberated electron.

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  Ionization energies of neutral elements (predicted beyond 104)

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  Combined potential of an atom and a uniform laser field. At distances r < r₀, the potential of the laser can be neglected, while at distances with r > r₀ the Coulomb potential is negligible compared to the potential of the laser field.

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  Schematic presentation of lambda type population trapping. G is the ground state of the atom. 1 and 2 are two degenerate excited states. After the population is transferred to the states due to multiphoton resonance, these states are coupled through continuum c and the population is trapped in the superposition of these states.

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  Feynman diagram for the process of double ionization in an atom through re-scattering mechanism