Primary Ionization

Leaving a wake in the sea of atoms…

OBSOLETE : Transfer to page Primary Ionization on

An electrical charge gives a particle the ability to act over large distances, allowing it to remove electrons from atoms in the material it passes through. This phenomenon is known as ‘ionization’, and the neutral atoms that have lost electrons have become ‘ions’. The greater the electrical charge on a particle, the greater its ionizing capability.

Ionization of an atom
A charged particle (here an alpha particle) with a large amount of energy expels an electron from an individual atom lying on its path. The atom with the missing electron has become an ion, with its electron structure disturbed and its interactions with its neighbours disrupted. The energy transferred by the alpha particle is eventually released in the form of electromagnetic radiation or heat. The alpha particle, as opposed to what is shown in the diagram, can also liberate electrons at a distance thanks to its electric charge. Most particles ionize hundreds of thousands, if not million of atoms before stopping.


Access to page in french

Related topics : Macoscopic effects, Effects of charged particles, Alpha Rays in matter, Beta Rays in matter, Effects of neutral particles, Gamma Rays in matter