(P) The electric polarization refers to the separation of charges in a material to form electric dipoles, or the alignment of existing electric dipoles in matter when an electric field is applied. The unit of electric polarization is dipole moment per cubic meter or coulomb per square meter(C/m²).

In cyclotrons charged particles are circular accelerated to bombard atoms. Short-lived positron-emitting isotopes are produced for Positron Emission Tomography (PET) imaging (e.g. F-18).

See also Linear Accelerator, Metastable Condition, Meson, Fluorodeoxyglucose, Electric Polarization.